US companies do frequently hire foreign workers. I worked with many at my last job. But there are still culture and language gaps to deal with, and even with foreign workers, these investment ventures couldn't hire enough people.

And the bigger tech companies with insane wages gobble up way more devs than they need, leaving it hard for non tech US businesses to hire developers. We didn't care because it upped our salaries, but now the flip side is we've trained normal businesses to see us as unaffordable. You can't just have a dev or two paid a living wage to maintain a website anymore, you need a whole team or else just outsource the whole thing to Vercel etc. We've consolidated much of the labor side to SaaS instead of regular devs in regular companies.

Anyway, I'm not arguing against the reality of supply and demand, but the sustainability of a demand side built off short term hypergrowth vs stable businesses spread across sectors. It's just another dot com bubble and I think it's not great for US society to have these extreme wage gaps, and not great for US business to basically invest everything we have into tech/advertising bubbles and not much else.