Yes and no. There are many distros, but they all use the same components. If outside entities only allow you to run specific distros or configs, you're done. Some examples:
* My jobs VPN only runs on Ubuntu. There is code in there that checks your OS.
* My bank wants the chrome browser. Messing with headers makes it work on firefox. But that's for now and needs me spending time fighting them.
* sssd is starting some light GPO enforcement on my laptop.
* systemd slowly moves towards encrypted home dirs and a fully validated boot chain. That's a golden cage with a lock to which we have the key. Microsoft can take the key away, and governements can make them do this.
* Android is also theoretically multi distro, but Google is the only one that matters. And they just decided they want developers identity.
* Most if the big sites make you jump trough hoops for non-chrome browsers. Facebook, cloudflare, Teams...
Computers are now part of networks, a bit like their own societies. These will force you to use their rules or isolate you. And that's assuming you can keep buying machines that are open or legally jailbreakable.