If that's inevitably the case, then we should all enjoy the ability to install user-controlled, open source operating systems while we still can.
However, if it's not inevitable, then those who cherish such freedoms should forcibly push back against the attempts to strip them away.
It's absolutely not inevitable since even opensource operating systems can work on providing attestation systems that aren't owned by big corporations and serve the user.
But just like with something like secure boot, they're missing the train and letting corpos dictate the implementation.