My background is in "neoliberal" economics rather than history, but I can try to answer your question as fairly as possible. I recently got into argument with a historian friend on this very same subject and I am pretty sure we were talking past each other, especially because this subject is so fraught and mixed with a left-right dichotomy that I think is deeply unhelpful to understanding what happened. So I am going to try to be as precise as possible, but keep in mind that a lot of very smart people will disagree strongly with what I write.

I would argue that some of Allende's policies (if they were continued) would have led Chile to an economic disaster. That said, Chile's economy didn't do badly under Allende at least initially. It grew by 1% in 1970 and 9% in 1971 before slipping into recession, although it's hard to seperate political instability from economic policy. Allende's policies can be summarized by a mass expropriation of land from latifundias, the nationalization of the Chilean copper industry, major expansions of public spending and large increases in public salaries. However, it is important to keep in mind that Allende did not invent these policies, but had pursued these policies had their origins in the policies of the 1938 socialist party government. For example, the state controlled about half of all investment when Allende took power and Allende they just accelerated the process.

Before I go any further, I want to take a moment to define some terms as I intend to use them. I am going to define neoliberalism is an ideology that argues that markets are efficient, and that solutions to market failures should touch the underlying incentive structure as little possible. The Latin American structuralists argued that poverty were the result of deep seated structures in both the domestic economy, and an activist government was needed to transform the structure of an economy. That said, these divisions aren't precisely left right in nature. Denmark's welfare state is largely constructued on a neoliberalism, while South Africa's Apartheid state likely inadvertenly followed very structuralist policies. My own biases and understanding of economics are very neoliberal, and I want readers to be as aware as possible of my own biases.

One of the major underlying theories of development was world systems theory and export pessimism. The fear was that wealthy nations would manipulate trade laws and organizations like the IMF and World Bank from ever allowing poor countries to export manufactured goods so manufacturing for the internal market was the only plausible path. The other was the Singer Prebisch hypothesis, that the long term terms of trade for commodity producers (Chile's economy has always been dependent on it's plentiful mineral, especially copper, reserves) were negative, so Chile needed to diversify away from exporting mineral resources. Third, the Harrod-Domar model, that the primary determinant of productivity is capital accumulation. Therefore, the key to development is the state redirecting the the profits from copper to (often state owned) heavy industry primary serving the domestic market.

To allow these domestic industries to succeed, the Chilean government maintained high tariff walls and a strong currency to dissuade imports. This strong currency was anchored in a fixed exchange rate, and an inflation rate higher than that in the US. Both copper mining and heavy industry are almost by definition capital intensive. A countries trade deficit is a macroeconomic identity defined as the gap between the savings rate investment rate. That is to say, the gap between exports and imports had to be financed by foreign capital. The moderate governments between 1938 and 1970 invited foreign capital, and even left wing radicals like Allende accepted the reality of foreign capital.

Moreover, Allende was guilty of macroeconomic populism. That is to say, he massively ramped up spending. Partly because of post-Keynesian (always be careful whenever anyone uses the word Keynesian to describe anything) beliefs of many of the planners, partly because Allende was at the head of a narrow coalition (Allende only one 37% of the vote in his 1970 election) needed wins immediately. However, these populist policies required running large budget deficits needed to be financed by savings putting further pressure on the current account. Moreover, high inflation combined with a fixed exchange rate will inevitable lead to currency appreciation. By 1972, it became clear that things were going poorly. Part of it was the uncompettetive nature of Chilean industry without infusion of foreign capital. Part of it was America deliberately blackballing Chile on international capital markets (I think these financial shenanigans, is much more important than direct CIA involvement), and part of it was Allende's policies.

That is to say, in 1972 budget deficit was 10% of GDP. Foreign investors were unwilling to finance these policies, so the government printed money. This printing of money led to hyperinflation of over 300%. The Chilean government nationalized vast swathes of industry out of ideological concerns, but they consumed rather than created foreign exchange and reserves plummeted to less than a month of imports. In that sense, Allende's government caused it's difficulties.

On the other hand the American boycott was a real thing, though I don't know how much of a causal factor it is. My gut filling is not a huge one. Moreover, Allende inherited these policies and almost all of Latin America (both left and right wing) would suffer the same problems when commodity prices collapsed in the late 1970s and early 1980s. Finally, it would be dangerous to lump all the left wing policies pursued as hurtful to the Chilean economy. For example, the Taiwanese government instituted, like Allende, instituted comprehensive land reform in the 1950s. These reforms strengthened agricultural production, and created the social basis for Taiwan's later boom. The World Bank has praised Mauritius's provision of universal education and healthcare because it created the political space for labor market flexibility. There are a lot of left-wing policies pursued by Allende that did tremendous (or could have done tremendous good if they had not been reversed by Pinochet) good.

I think the narrative I have stated would not get a consensus approval from historians, although I suspect most Economists would consider my account fair. So no consensus, although I do think my stance is at least intellectually defensible.

Follow-Up: Do Historians agree that the Chilean economy did badly in the early 1970s?