2/3/4 -> FAANG have a ton of money but no incentive at all to spend it on philanthropy. I wish it was not the case, but their only job is to make their investors happy.
3 - is it dishonest ? For sure there are some kids in SV, LA,etc that could work in tech if they got the education but the thing is, they didn't. Also, local talent is never going to compare to the global one.
I would love to see laws pushing FAANG and co to invest in philanthropic causes. Heck, I would not even mind if this was based on taxation. But cutting H1B is not going to solve any of these problems.