There is too much hyperbole here.
The world is going to become multi-polar. The US has no capability to stop this. Yes, it can make China's life more difficult and will, but it won't stop China from being a superpower in the long run, the momentum is too strong, China's population is too big, it already has a huge pool of educated people and is already the world's largest industrial and trading power.
But does this mean if the US will collapse? That's nonsense. The US will remain a superpower, but will have to deal with another superpower in the world. Neither China nor the US can dominate the world. The world will be split into many poles of influence with Russia, Europe, India, various Muslim countries, Brazil all retaining influence. There may be a day when an African state becomes strong enough to start exerting influence and becoming a local pole of power as well, I would be money on Ethiopia for that.
The world is going to be a messy, chaotic, loud and angry place. But gone are the days when one hyperpower ruled the world. In recent history, only two states have come close to that position. The first is Britain in the mid to late 19th century and the second is the United States after WW2, the US completely dominated and had the lion's share of the world's financial, industrial muscle.
That day won't return. China will be a superpower but it will hit resistance in many paths that its power will be constrained. The US will also have to deal with a diminished role while still retaining a position as a superpower.
De Coupling with China will happen but the American Manufacturing jobs ain't coming back as Trumpers believe just shift out to Vietnam,Indonesia or the big cake India they really want India to be their poodle now folks like Steve Bannon and Peter Thiel would love that but it will hurt China short term as China isnt a cheap labor powerhouse like it was in the 90s 2000s China wants to be big boss basically now decoupling and tariffs would have worked under Slick Willy or Dubya
I use to think Communism was shit system again being product of the US society you are thought to believe the so called Free Market is everything and All the horrors of Communism granted Communism is a shit system but Capitalism is utter shit system as you described capitalists made concessions after the Great Depression and WW2 to weaken labor rights and labor unions by giving Social Security and later Medicaid but look right after 1992 when USSR bite dust no more concessions for working Americans tho process started in the late 70s under Carter later accelerated under Reagan then super accelerated under HW and Clinton
Some of China's manufacturing may shift to India, but I think companies that move to India will soon hit a reality check. Lack of infrastructure, brownouts, a less disciplined workforce, higher shipping costs, farther from other industrial supply chains, etc will probably raise their operating expenses even if they can save a bit on the labor.
China has already been moving away from cheap labor intensive manufacturing since 2010. The fact that armchair generals keep harping about how moving T shirt and shoe factories away will make China collapse is almost comedy tier.
The real key is whether China can move up the ladder without access to Western, mainly American investment and technology. They've been a reasonably strong domestic research capability, capital market and market for it, but that's still up in the air. If even with massive tech sanctions, China can overtake established semiconductor and chip fab companies, advanced industrial machinery makers, Boeing and Airbus, then China will pretty much be in the clear. If not, China will be stuck in the middle income trap.