Google outright lets you unlock your bootloader on Pixels, and relock it with your custom keys, and even tells you how to do all that in the docs. You lose Play Integrity certification which is where things are getting a bit messy.
But for that you have to blame Amazon, Netflix, Hulu, Disney, a lot of banks, a lot of games for using what is basically DRM for apps. It's the developers that want those features, so you can't mod their APKs and take the ads out, make sure you download the official version from Google Play because dumb users getting scammed and all that stuff.
I run LineageOS on my phone, I'm not doing anything whatsoever to hide it, and pretty much everything works perfectly except Google Pay. Which I guess is fair game, I hate it but there's a reasonable argument to be made there.
The rest is the same DRM woes I deal with on Linux, I value my rights and freedoms more than running an app.