The problem is doing it as a company. IBM wasn't defeated by hobbyists building their own PCs. They were defeated by other companies reverse engineering their BIOS and selling their own IBM compatible systems. This isn't possible anymore. It just means you get buried in lawsuits until you go bankrupt.

https://www.eff.org/deeplinks/2019/06/felony-contempt-busine...

It's not your phone, it's theirs. They're just letting you use it, and only if you're a good boy who follows all their policies and terms and conditions. Subvert this in any way and it's a felony.

It is. 17 U.S. Code § 1201 - Circumvention of copyright protection systems