Ehhhh… sorta maybe. Ultimately they can’t, but they can make development more difficult.

Also Google has nothing to do with whether or not you’re bootloader is unlockable. Get a phone that is.

If you rally want to go down the whole FOSS path it does ultimately become a bit of a lifestyle.

Just use a custom ROM. This sadly will affect app developers. But if you are on a custom ROM without GMS it will continue to work just fine.