You can only make money if you produce value. If you stop producing value because your old industries decline/collapse and you miss out on new industries, your wealth will trend towards that of a third world country.
Maybe. I would contend that wealth accumulation over the long term is a function of the strength of local institutions e.g educational, judiciary etc. This is effectively the thesis of ‘Why nations fail’. Europes relative decline will only continue if the institutions of the US (and others) continue to be robust and healthy. I am not sure if this can be relied on into the future.
The current question is whether being the minor partner in a relationship with the US or China makes for a better & more free society.
Westphalian norms are falling apart and countries will need to make hard tradeoffs about how to build enough economic heft to maintain their cultural values.