So, OS-level age-gating is going federal, which will effectively kill your rights to device ownership and what’s left of free speech and expression.
Enjoy your free speech while you still have it because this is a clear attempt to erase that right.
SOPA never died, it just went into hiding until time to reemerge, and now’s that time, this is basically SOPA in a save the kids trenchcoat.
It is not always the case today. For instance you can now use Linux on your computer with a local account called anything you like, not tied to your identity in any way. That, by the way, used to be the case with Windows too, until Microsoft killed local accounts not too long ago.
In an age-verification world, a Linux distro that can be legally used in the US will have to connect to a third party that can certify your age somehow; I haven’t read enough on this to know for sure, but I can’t think of a way to validate your age without telling that third party who you are, uploading your id or similar privacy-unfriendly things.
That way, the third party will have acquired a power to limit or deny you the use of your device (plus a bunch of your personal information).
Then, to make this work, your OS will have to store your age (and hopefully only that) and share it with any of the installed apps that need to verify it, which opens its own can of worms.