I've been thinking about the 'success' of the Marshall Plan relative to the massive failures of the various attempts to repeat it that spent significantly more money (off the top of my head: Vietnam, Balkans, Afghanistan, Iraq) and I've come up with a few things that seem like they were present in the Marshall Plan but not in the later, failed copies.

A) Rebuilding democracy versus building it. Most obviously, it is easier to get everyone to end up in a place when they have already been there. Konrad Adenaur, for example, was first elected Mayor of Koeln under the Wilhelmine Empire, and had first won an election 40 years before becoming Chancellor (with a dozen year interregnum, spent in obscurity during the Nazi era). Similar story w.r.t Japan (Yoshida Shigeru was a diplomat rather than an elected official, but had the same sort of career, right down to the big hole where he had no official job during the war). The main Axis nations had been reasonable democracies within the past 15-20 years, whereas Afghanistan and Iraq were farther from that (and their initial leaders were refugees rather than people who had stayed, which is an enormous difference that I think US leaders missed). The USSR obviously was a lifetime since the last real, multiparty elections in 1917.

B) Many nations working together. The Marshall Plan aid was distributed across most of Europe, and in a way that emphasized international cooperation (with 25% going to the UK, 18% to France, and 11% going to West Germany, it truly was split among many nations). This helped to rebuild international trade that truly cemented the nations together. This is plausible for a USSR modernization, so long as the Russians are willing to admit that the other nationalities are truly independent. (The most successful of these attempts, in the Balkans, largely did manage to tie the international knots together. The others not so much. But how much of that was that Slovenia and Croatia are great vacation trips for Europeans, in a way that going to Moscow was simply much more distance?)

C) Continuing presence of US troops. Japan's economic growth really dates to the Korean War, when the US military suddenly energized and needed local production to supplement weapons and goods shipped across the Pacific. Similarly, from roughly that point to the end of the Cold War the US had a quarter-million men in Germany alone (more in the UK, Italy, etc.). Those men needed goods and services, and had dollars to spend. This is basically impossible to imagine for the fUSSR. (In Vietnam/Iraq/etc. the US military obviously had a continuing presence for a long time, but it largely provided its own food and supplies, rather than depend on the local economy. Lots of money did leak into the local economies, but not in economically beneficial ways- read much of it was captured by graft.)

D) Humiliation: this is important point that is something of a combination of A and C- there was a complete and total defeat, with most of the country smashed down to rubble, which made the democratic history seem attractive, and a massive continuing US presence, which seems to have prevented Dolchstoss narratives and backsliding from taking hold. This seems incredibly unlikely for the fUSSR to me. Even at their lowest, they were an independent country with a massive nuclear arms cache and quite a bit of (well-justified) pride in, e.g. Yuri Gagarin, Sputnik, and Sergei Korolev.

Basically, this isn't about money: the US spent about as much on civil reconstruction (excluding military expenses) in Afghanistan alone, as it did on the entire Marshall Plan in all of Europe adjusted for inflation (using CPI-U, the most common gauge). So there has to be more than just money, and I'm skeptical that the US had significant power to make the former USSR outcomes better.

Certainly, any discussion of a successful fUSSR Marshall Plan would have to start with why the Baltics outcomes are so much better than Russia, and I don't have much of a story for that.