Yes, most of those new bigtech/startup employees are getting compensation in the local band. But they are in the very top of that band, and gradually shifting it up as US companies compete for talent, and
VC-funded local companies start competing more seriously as well.
It’s a gradual process but in my experience it’s very real.
This gradual process might also happen because compensation has to cover the costs. While some things have kept their prices seems to me some services have gone way up. I was just discussing that a hotel we went to long ago basically tripled their prices. Real estate is also up.
There are some lucky few that still manage this or some that even manage to get US-level rates doing open source but that's like winning the lottery; outliers.