Signal is one example. Their values are simply not compatible with what the Chinese government wants (local data storage, key access, etc.). Instead of complying and putting their users' privacy at risk, they accepted the ban.

Google, out of all companies, also decided to partially walk away from the Chinese market in 2010 over censorship concerns [1].

Nobody is forcing Apple to do business in China, or the UK. They actively choose to do so, and because of that also put themselves in a position where they have to comply with these laws, presumably because it makes them more money.

[1] https://www.nytimes.com/2010/03/23/technology/23google.html