What would be the point? If they don’t remove it, do you imagine they’d still be selling iPhones in the country?
Actually - yes I do. Any action against Apple would be a huge blow to both the Chinese and American economies. I'm sure China wants to do that, but right now they cannot do it.
Do you think anyone has ever criticised X Jinping in iMessage? Obviously the answer is yes - and yet iMessage is allowed while every other major (foreign) social network has just been banned. iMessage is now the only major foreign messaging platform allowed in China. That's not a coincidence - it's because so many iPhones are manufactured there.
It's also pretty clear Apple is transitioning to manufacturing elsewhere. They're on schedule to manufacture a quarter of iPhones in India by some time this year (up from zero not too long ago) and are dipping their toes in South American manufacturing as well. Banning iPhone sales in China would rapidly accelerate those plants.
Apple's contribution to China's economy is substantial - those manufacturing plants are huge and have hundreds of thousands of other companies supplying them. Also the workers are very well paid (for a factory job in China).
Yeah you'd be wrong. Apple is very open about how the security model works - which is similar to Signal and fully encrypted. The only way to decrypt a message is with physical access to one of the sender/recipient's devices.
Their claims about how it operates have been confirmed by open source developers reverse engineering the protocol (e.g. Beeper).
There is one workaround — device backups can be accessed and depending how you backup, your message history is likely in there (you can do encrypted backups, but that means data loss if you forget your password or an attacker changes it on you which would happen, lots of money in a ransomware attack like that). However even then – all your other devices show a popup message if you restore from a backup - warning that a "new device" has access to your messages.