FWIW, 200-300k is not that uncommon far outside of FAANG or the usual tech cities for experienced senior engineers with current skills. We are not even talking startups necessarily but boring industrials and other companies no one thinks of as tech companies. Every large business is being forced to be much tech savvier and this reality has diffused high-paying tech jobs among a much wider range of companies and locales.
You are correct on one point: most Americans don't have the skills for these jobs. That is why these jobs pay so well, almost definitionally.
It is trivial, in the US, for someone to work at the older large tech companies and get over $300k just by staying in the job. Your typical SWEIII is making $220k base with a 20% bonus and gets roughly 50k/3 RSU grants each year. After 3 years, that's $50k annual due to stacking. This for relatively easy big company roles, and not even lead.
You are correct on one point: most Americans don't have the skills for these jobs. That is why these jobs pay so well, almost definitionally.