I can’t say who will win or lose. The value of a social network has as much to do with its userbase than its tech, so maybe Meta has a different path. Alphabet and Microsoft are who I really have in mind here.
Iterating an existing product takes time, but creating a clean room clone of an existing product could be accelerated significantly with AI. We could be moving towards an environment where bigtech falls back on one of its core competencies (scale) and hoards infra while small startups pay them compute and inference costs to undercut existing consumer-facing software on price.
Depends what your threat model is, but this will literally turn you into a glowing signal that says "hey, look at me!" Your face might be protected but anyone manually reviewing security footage will be paying way more attention.
A subpoena isn't "simply asking." Subpoena literally means "under penalty" in Latin. If the company does not comply they will be held in contempt of court and someone may well go to jail.