> American tech salaries, on the other hand, are inflated by exaggerated tech stock valuations

How does a company’s stock price affect salaries? Companies only receive capitalization (via stock) at IPO.

Stock market valuations do enable higher total comp through RSUs / options.

At best very indirectly by having to compete with "lotto tickets" in theory for start ups and total compensation but in practice not really since the sensible default financial assumption when factoring in equity stake at a random start up is "worth $0 because it will probably fail".

I believe it is not /willing/ to as opposed to not able to judging by GDP per capitia.