One very questionable conclusion: The ambassador did note that Russia never really recovered from the Soviet collapse. However, what he missed was the comparison: Ukraine did worse.
Let's just look at defense economy as an example. As background, Ukrainian GDP per capita fluctuates between 1/4 and 1/2 of Russia's every year since 1991. The only reason Ukraine is even comparable to Russia is because of size, being 1/4 of Russia's population. Post 1991 Russia at least kept its oil/gas/aerospace industries alive. Post 1991 Ukraine inherited a huge chunk of Soviet manufacturing including a space program, gas turbines and jet engines (Yuzhnoye Design Bureau, Motor Sich, Antonov) and failed to turn them into anything useful except ironically, selling their products back to Russia. The result is that Ukraine basically only had a few years of economic growth from 2001-2008 after the instability of the 90's and the financial crisis followed by Russian annexation of Crimea and breaking off of Donbass.
After 2014, they (expectedly) sanctioned Russia, which crippled Russia's naval modernization until Russia could build gas turbines again, but this was not costless. It also meant that they lost their biggest market by far. Nobody else really buys their stuff in bulk.
and
.
, which led to a
and a refusal by the IMF to issue further loans.
OK. Let's say that Ukraine succeeds in stopping Russia from winning. What next? Right now normal economic activity in Ukraine has stopped.
This isn't from monetary problems, this is from losing means of production. More dollars won't fix it. This is just from 3 months of war.