What I find almost satisfying to watch is how the US throws away the soft power it spent nearly a century building for very little benefit in return.

The thing is that soft power is extremely effective. Many other countries, including China, try hard at acquiring a fraction of the soft power US naturally had.

Trumps administration, sooner or later, will pass. Whether it is voted away, or if it turns into a form of dictatorship, at some point in the future it will not be there anymore. The US won't be able to return to "how things were" when that happens. New trade deals, new alliances, a different ordering of things will be in place.