“What do you mean by it has lost everywhere but is now returning?”

By that I mean the USSR was the great socialist state, with the whole of eastern Europe joining. There were socialist revolutions popping up everywhere and even the United States got scared during the 1930s prompting a New Deal capitalist reform to a more social democracy in order to appease the working class.

“Are you saying it has a chance to win, permanently?”

The only reason socialism has failed in the USSR is because of the US.
During the 20th century the US had every tailwind it could wish for,
the USSR had almost every headwind.

The US biggest advantage is it’s total amount of fossil fuels. It simply has the most of it, which is why it was able to produce more oil and gas than the rest of the world combined in the first half of the century.
It also has produced the most coal in the world during the entire 20th century and still has by far more of it than any other nation.

And then on top of that, two world wars where the US was almost not attacked at all, whereas the Soviet Union was the main target in world war II, where 90% of the fighting happened.
Enormous losses.

Only now is it beginning to look difficult for the US to hold on to it’s hegemonic power.

With having such a tailwind, the US in contrary to the USSR, has lived like a king despite being reckless. For example, to produce fossil fuels, the US just took as much risk as it liked and ‘hit gold’ every single time. The USSR could not understand why it took them so little time when they were carefully expanding their production.
Since the dawn of the 21st century however, the US has tried to repeat this method with shale oil, but this time it’s backfiring. Initially everyone jumped on board again, trying to turn the US into another Saudi Arabia, because why wouldn’t it be #1? And in just twelve years they managed to indeed beat Saudi Arabia, producing the most oil in the world again…without a profit.
So instead of being as earn as much as Saudi Arabia, they got into debt.
Investors walked out after twelve year of constant production increases.
This leaves no money for the shale oil producers to take risks and so currently the shale oil are now drilling all the wells they’ve found, until they can pay down the investors and earn enough to find new wells. They’ve got about two years until they run out of old wells.

Then there’s the US biggest advantage of the 20th century, coal.
Wind and solar are beating coal and US wind and solar is less advantageous per capita than coal for countries like Tanzania, Chile, Indonesia, Tajikistan, or the North Pole for that matter.

Now having lost these advantages, the US has gone into the 21st century thinking that communism has been beat and won’t return forever, so it doesn’t need to repeat what it did in the 1930s, which saved the nation from a socialist revolution.
And so there will be a revolution in the US, socialist or the always-self-destructive fascist one and that will be the end of it’s world reign.

So without the US being the big spoiler in the room, there’s the question of why won’t there be a capitalist nation taking over the baton.
First of all China will likely be the new big winner and China is socialist.
Second of all, automation causes jobs to be lost and we are in a very late stage of automation.
It’s been happening since the industrialization, but with computers, not just machines, all jobs are at stake. Jobs in the agricultural sector, industrial sector, service sector, all of them.
Even the profession of a banker is no longer safe with the introduction of digital currencies.
And this type of automation, computerized automation, has been happening for 50+ years already.
The richest people of the world already are semi-IT nerds instead of bankers and IT is the profession of job destruction.
So the richest people in the world, the thing that makes the most money these days, is the profession of automating other people’s jobs.

This is destabilizing all capitalist nations, which means that after the US collapse, there’s not going to be a new capitalist nation.

Permanently.