They never had that. e.g. Apple.

To be more specific, it would be Apple preventing you from doing it in this case.

If you had a phone that let you install software on it of your choosing then you could install whatever you want, regardless of who Apple isn't allowed to do business with. They made themselves a chokepoint, so now they're a chokepoint.

The internet interprets censorship as damage and routes around... no, your phone's only route is through the one corporation.

You're free to jailbreak your phone if you want to exercise that right. And Apple is free to deny you updates and service if you do that.