Do they bring jobs and tourism and money? Do they help bring technology and educated individuals?
This is a question that might be more suited to another subreddit like /r/economics, but there's at least one example from 20th century history that I think could be a useful introduction to this. As a disclaimer, this is by no means my area of academic specialty, but aviation is an interest of mine and I've looked at how infrastructure's developed around the world out of curiosity.
With luck, someone who's specialized in this will be able to answer in greater detail, but I hope this helps a little.
Boomerang money: I'll use Tanzania as a representative example, simply because that was how I first started learning about this, and because elements of Tanzania's development during the 20th century mirror North Korea's in strange ways . P.J. O'Rourke in Eat the Rich wrote a travel essay about the country in which this term figured prominently in a description of the economy's problems. In short, boomerang money is what happens when someone or something invests in a country but most of the profits don't remain there. For example, if you go on safari in Tanzania, odds are pretty good that:
So "boomerang money" is money that comes to Tanzania, stops briefly, and then leaves. Foreigners love to come see the beautiful landscapes and animals, but they're generally spending money in places where the profits won't remain in the local economy.
That doesn't mean that Tanzania doesn't benefit from tourism, because it clearly does. By the World Travel and Tourism Council's recent estimates, it's ultimately responsible for about 13% of Tanzania's GDP (warning: PDF). Hotels and airports and restaurants employ locals, and tourism also benefits locally-owned shops and people who work as safari guides and park caretakers. It's just that a huge amount of money associated with tourism (and perhaps even most of it) doesn't remain in the country, which is problematic for Tanzania's long-term growth.
So why didn't Tanzania develop any of this stuff on its own? This, bizarrely enough, is where Tanzania actually bears an eerie resemblance to North Korea, which is my specialty and had an equally interesting trajectory in 20th century history. (And that's in addition to its flag carrier being the world's notorious "one-star" airline, but that's not what you're asking about here.)
Anyway! Tanzania had particularly bad problems with economic growth due to Julius Nyerere's policy of ujamaa between 1961 and 1985. Nyerere was the country's first president after Tanzania's independence from the U.K., and he implemented a very aggressive set of policies to transform the country into something approximating his vision of a more perfect African society. Some portions of ujamaa bear a strange resemblance to Kim il-Sung's policy of juche in North Korea, and both had the effect of isolating their nations from the international economy.
Now, ujamaa wasn't all bad, just as juche wasn't all bad. (Although I'm sort of using juche as a blanket term for Kim il-Sung's social policies in NK, which is not quite historically accurate. I can clarify later if you need.) Their respective emphases on education and the improvement of health statistics were actually very, very good. However, the forced collectivization of agriculture, nationalization of industries, and mania for "self-sufficiency" in both nations absolutely destroyed their economies; both countries became, and remain, heavily dependent on foreign aid. Nyerere and Kim il-Sung brooked no dissent and authorized their respective militaries to shoot or imprison the people who protested. Nyerere was never quite as cruel about this as Kim il-Sung was, but I'm sure the distinction didn't matter too much to the millions of Tanzanians who were forcibly uprooted and relocated (warning: PDF) during the "villagization" of their society.
Neither Tanzania nor North Korea studied or developed the kind of societal or physical infrastructure needed to support things like wide-scale tourism or international business. Neither of their leaders saw these as desirable for their societies at the time.
So what does this have to do with airports? The reason I bring all this up is because airports are a crucial part of a modern economy, but they're not something that just anyone can build, run, or maintain. When developing countries need to build or expand airports, they often find themselves buying the knowledge and productivity of developed countries in order to do it. Without better education and investment, nothing about that is likely to change.
So if we're going to look at developing countries around the globe and ask how airports benefit them, we have to ask:
Often the locals don't have the expertise or experience to build airports to international standards (or, as is common in former colonial outposts, expand or improve on whatever infrastructure the colonial government left). For example, Julius Nyerere International Airport and Kilimanjaro International Airport contracted with a Dutch company to add additional terminals and expand their capacity, and that's a pretty common practice in the developing world. If your country doesn't have the materials or experience to improve its air infrastructure, you pay someone else to do it.
So, as a TL:DR, I believe the ultimate answer to your question is a Yes, but ...