Erm, yea, what about countries with socialist leanings like the Northern European ones? They do occassionally seem to have, like, the best living standards in the world for actual countries, some of 'em, iirc?
They're soc-dems, which is generally the best approach: democracy as usual with a comprehensive social safety net and progressive taxation.
Is there something inherently corrupt about socialism and/or communism?
No, but they're functionally impossible to institute properly on a large scale due to the simple fact that there will
always be enough people willing to spite the system for the sake of personal power and financial gain. Like presidentialist democracy, they're also poor choices for countries which have only recently thrown off authoritarian rule, as those authoritarian patterns of control and obedience are ingrained and easy to backslide into when the system makes it simple for a central executive to consolidate power.
The argument could easily be made that the USSR would not have been nearly as shit if literally every other country on Earth didn't have it out for them.
If the West hadn't been half-assedly backing the Whites during the civil war, the Bolsheviks would have consolidated power sooner. It wouldn't have changed their leadership, it wouldn't have changed their inherent ideological drive. Communism was wholeheartedly and explicitly devoted to overthrowing extant political and economic systems. It's hard to understand for people born more recently and away from affected areas, but pretty much all of Europe pre-WWII was heavily fractured ideologically. The fear of leftist revolution actually spreading as Marx predicted was one of the primary driving factors behind the dawn of the right-wing reactionary politics that birthed fascism. The USSR was locked into a fight for survival with the rest of the world, but it was one of their own making.
Don't idealize the USSR. I'm a dirty leftist, but I still think that it was a fucking travesty. They did as much harm to the working class as the empire it succeeded and the plutocracy which succeeded it. The PRC came out of things okay only because they could afford to waste absolutely obscene amounts of resources and sickening numbers of their own people brute-forcing industrialization and modernization in a selection of ways of varying stupidity. Cuba came out of things all right because it didn't go full crazy and had a dictator who was only a moderately oppressive ass instead of a murderous delusional paranoid self-aggrandizing moron.