The talent isn't being converted from potential - as was recently said, "You can't be what you can't see".
I was in Kansas City meeting people in Jan and it's pretty clear that there's a lot of talent hiding out there in downtown Missouri.
The talent there tops out at SSE because there's no vertical space without jumping to management & two years down the folks know are "mid-west-nice" managers with an iron fist behind it.
Several people who should've chased down the principal engineer roles have become these sorts of managers who never made it to directors because they're always been better devs than they were managers. And this seemed twice as bad for the young uns to have a dev-heavy manager squash a few of their attempts to actually own decisions, instead of just proposing them & see that role as a way to get that ability.
Most folks though things would be different if they had moved to SFBA, but all of them hit this point when they already had kids in school with stable single-income households (house all paid for).
In fact, I'd be one of those people in Bangalore if I had a bit more skills as a manager (completely sucking at management is a good way to be forced to chase the dev side).
If they could hired as a principal dev via remote out of being promising senior se, then this process would actually convert a lot of the talent into actual productivity in the industry.