It's too late to close that Pandora's box. Linux is far too ubiquitous now. Even if it still lags behind Windows in the desktop computing space, it is already a non-trivial market share and growing quickly. And in many other computing spaces, Linux is king.

They can't realistically make Linux illegal. But they can put onerous requirements on popular Linux distributions - such as the age "verification" features they're currently trying to require[0]. Hopefully that proves to be ineffective.

[0] https://agelesslinux.org/distros.html