Your question is difficult to answer because it's essentially alternative history, in theory the CIA intervention in x country could have made the lives of the people better, however because we don't know what would have happened if they didn't, it's essentially alternative history. It's basically guessing based on probability. That said, I will try to give an answer.

Following world war two, the allies - as with the majority of western european countries under allied occupation during the time - pushed that Italy be a democracy, to which the 1947 Italian constitutional referendum was signed (thus abolishing the monarchy during the time) which paved the way for early 1948 elections.

Whilst the allies (this I mean the CIA and British intelligence) hadn't necessarily backed a party during the time, it was widely believed that the communists would not win the election. It was thus worrisome for the allies when the Popular Democratic Front (Italy) (an alliance between two communist parties during the time), made strategic gains in polls before the election. The election was heavily covered in western countries, with the Time magazine even claiming that 'one Washington official called [that election] more important to the U.S. than its own presidential election next November' citation.

It was a dirty campaign, probably the most aggressive in terms of advertising between two opposing sides in an election during the time, and likely also symbolic of how deep the east-west divide (communist vs allied) was. "the most passionate, the most important, the longest, the dirtiest, and the most uncertain electoral campaign in Italian history", according to historian Corbi cited in the book 'From Fascism to Democracy'.

In the end it was decided, by the allied leadership during the time, that it was too big of an election to lose, a loss there would (in their train of thought) result in aiding the exponential increase of the sphere of influence Stalin had achieved post WW2 (an insight into the origins of the domino effect). As a result it was decided the CIA would intervene, '"We had bags of money that we delivered to selected politicians, to defray their political expenses, their campaign expenses, for posters, for pamphlets," according to CIA operative F. Mark Wyatt, citation. The CIA ended up funneling $1 million to Italian center parties (a lot for an election at the time, this just for the center parties, not the other right wing parties possibly funded) and published forged letters in order to discredit the leaders of the Italian Communist Party. It also undertook 'a campaign of writing ten million letters, made numerous short-wave radio broadcasts and funded the publishing of books and articles, all of which warned the Italians of what was believed to be the consequences of a communist victory.'

In the end, the 'Christian Democracy' party ended up winning 48.5 percent of the vote. Thus preventing the communists from taking power.

It could be said without the CIA intervention, the communists would still have been pushed back, however their backing certainly did help them in the elections. I write this with the presumption that the communists would not have 'improved the situation of the people'.

Though this is more a question for r/economics (debate about economic systems) and politics (communist parties in power at the time tended to be dictatorial to towards their people) and as said your question is essentially alternative history, which is difficult to answer.

tldr; having an essential part in pushing back the communists in the Italian 1948 election, thus preventing their rise to power, the assumption being the proposed policies of the communist party would not contribute to 'improving the situation of the people'

I'll go ahead and try and answer. I've just finished reading Legacy of Ashes by Tim Weiner (http://www.goodreads.com/book/show/970488.Legacy_of_Ashes). It's a detailed history of the CIA since its inception as the OSS up to the mid-2000s. He based the book off of tens of thousands of declassified documents, interviews with CIA agents, and 10 Directors.

To sum up the book and your question in a simple answer...Not really. The CIA attempted coups in a host of countries (Iran 1951, Guatemala 1954, Syria 1957, Indonesia 1958, Congo 1960, Cuba 1960s, Domincan Republic 1961, South Vietnam, 1963, Brazil, 1964, Chile 1973, Nicaragua 1980s). Some, like Iran, Domincan Republic, Brazil, Chile, Guatemala, were successful, and others, like Indonesia, Cuba, Syria, and Nicaragua, were not. Even when a coup was successful however, the CIA often backed or funded absolute monarchs or military dictators, such as Congo dictator Mobutu Sese Seko, and often removed legitimately elected governments. These new rulers often cracked down on their enemies and the public. (https://partners.nytimes.com/library/world/090897obit-mobutu.html) (https://msuweb.montclair.edu/~furrg/langguthleaf.html).

But, keep in mind, the agency was never designed to help or benefit other countries. It is the covert arm of American foreign policy and seeks to benefit the United States. Ultimately, especially during the 1950s-1980s, its goal was to fight the spread of communism and contain the influence of the Soviet Union. The CIA and American leaders at the time felt that stopping communism was more important that worrying about overthrowing a few democratically elected governments.

However, and the book goes into great detail, covert action is only successful when it is actually covert. Too many of their missions became front page stories or, while hidden from US citizens, were obvious to the countries they were infiltrating. Two great examples come to mind.

While attempting a coup in Indonesia in 1958, CIA pilot Allen Pope was flying bombing missions with a B-26 against Indonesian government forces. Over the course of a month, he flew several sorties, sinking 3 cargo ships and attacking Indonesian air bases and military positions. His plane was shot down and he was captured, with incriminating documents on his persons. He was eventually released in 1962 after a plea from US Attorney General Bobby Kennedy.

In 1957, the CIA sent an agent Rocky Stone into Syria to help lead an overthrow of the government. He was immediately discovered, set up, and expelled from the country in an embarrassing political situation. u/smokinbluebear goes into much more detail in this post (actually from the same book). https://www.reddit.com/r/conspiracy/comments/2ipydy/in_1957_syria_became_the_first_arab_country_to/

The CIA has had some legitimate successes, although they are few (or still classified). The successful support of the Mujahideen in Afghanistan in the 1980s helped drain the Soviet Union and arguable assisted in its downfall. The sneaking out of several US embassy workers after the fall of the embassy in Tehran (as highlighted by the movie Argo) was undoubtedly a success. But both of these incidents show the double-edged nature of the clandestine services. Yes, they did a great job getting our citizens out of the country in Iran, but arguably they caused the problem by installing the Shah to begin with. And they supported the Mujahideen, but that also helped give rise to the Taliban and al-qaeda.

The CIA's greatest successes have been in its intelligence gathering, not necessarily it’s in covert operations (or we just don't know about them). They fostered the development of the U-2 and spy satellites (the Corona project) which gave the US an unprecedented look at the actual strength and weapon capacity of its enemies. But it’s not hard to imagine that we are not well thought of in the countries where we helped participate in a coup. Those populations were negatively affected, sometimes for decades. Even if there were short term gains for the United States, long term foreign policy certainty was affected negatively.

The question seems too broad - surely every CIA intervention has improved the situation for certain groups of people within a country...

CIA supported Solidarity workers union in Poland and other democratic movements in the Eastern Block. This support took form of advice, cash transfers, equipment deliveries (mostly printing machines for printing of independent newspapers banned by the communist regime and radios for communication) and intel sharing. This support was almost exclusively provided through third parties (Western trade unions, churches, human rights groups) but it is absolutely confirmed that it was CIA behind it.

Solidarity movement, which at the highest point had 10 million registered members (in a country with population of 38 million), is considered to be one of the major factors behind the collapse of Soviet Block and communism in Europe in general.

The fell of the authocratic communist regimes in Central-Eastern Europe brought tremendous improvements in terms of democracy, respect for human rights, freedom of press, government transparency, as well as economic situation. While there are certain groups that are relatively worse off than they were under communism, the vast majority of the populations of countries like Poland, Czech Republic, Hungary or Romania are currently in incredibly better situation than they used to.

I recommend Supporting the Revolution: America, Democracy, and the End of the Cold War in Poland, 1981--1989 by Gregory Domber as a further reading on that topic.