Sorry about the (whiskey-fueled) rant and all, but it's true. No more Soviet Union or Eastern Bloc, the Gulf War was held as a demonstration of how the US would take care of the bad guys as the world police...they had it all at this point. Whatever European leftist parties remained practically held a race to see who would turn succdem the fastest.
So how did they manage to fuck it all up? Socialism and communism were all but eradicated, but even if it's just a small internet space, there are people here from the imperial core who still think there's something to these theories, despite the fact that most of us were probably told from our childhoods that gommulism was something evil that used to exist, failed, and then ceased to exist in 1991.
My own theory is that capitalists got too greedy. In the 1990s there was this whole 
thing of saying "well, these factory jobs might disappear, but they can just get a better education and therefore better jobs" and a lot of people went along with that, accepting that the people who lost their jobs were a lower class of people, incapable of simply bootstrapping themselves into a better existence.
At the same time, anyone who thought there was something wrong with this system were treated with a mixture of amusement and mockery. How could there be anything wrong when we were doing so well? There was a token opposition to capitalism that was allowed to exist because they were amusing, like Rage Against the Machine was on a major label but most people probably didn't even listen to the lyrics.
There was unironically the foundation laid here for the End of History, not that everything was actually great in the world, but if the capitalists had allowed the people to just afford their treats, then nobody would've even noticed the exploitation of the global south that allowed them to have their treats in the first place. It was the perfect scheme, but of course the 
on top wanted more, so they started screwing with everyone's livelihoods.
Again, sorry for this terrible post which is barely structured at all. TL;DR: capitalists had it all after the USSR ceased to exist and we wouldn't even be here if they just could've refrained from ruining everything to make a slighty bigger profit.
edit: The tendency of the rate of profit to fall is something I should've considered when originally writing this post, because obviously that's a big one for why things couldn't just keep going like in the good days after before 9/11.
Yeah, somehow we're still here.
Part of what I attribute this to is just that the systems were inherently contradictory and never sustainable, the ones which were setup to get enough professionals working on automating the ruling class' dreams of technological supremacy over the planet (or ability to escape it a la WALL-E or in .nz bunkers or whatever).
Also enough of the present ruling class has bought the market mythology wholesale and internalized it and actually thought things worked that way, a lot of them were just scions of an existing fortune and never had to actually think about it or learn how to keep it afloat. True believers. Or they did happen to succeed within it, eg tech companies' founders can be from less bougie backgrounds and just become parrots of the propaganda. But obviously that isn't a possibility for everyone. So it starts to break down for at least some of us.