Linux

Of course, legislators are getting more and more technically knowledgeable so trying to rebel against OS age verification by simply cosmetically making a computer different from your typical desktop like systems might not suffice...

I'm admittedly not especially familiar with how law is practiced in the US but in my opinion trying to skirt the letter of the law while blatantly violating its intention is usually a bad idea. The more you piss off prosecutors and judges the more effort they will put into finding something to prosecute you over, and it also makes them more likely to push for the harshest fines/convictions that are legally possible.

Of course a lot of the time the law is just bullshit, and this particular bill appears to have at least a few issues, but still...

Nevertheless, I did not know about Cage! At least now I know how the hacks make those IoT control panels with their SBCs! Perhaps I'll set up something cool in my living room like... A weather forecast screen? The stock market? Live GPU prices?

For completeness sake, Cage isn't the only way to do this. Gamescope is another popular "kiosk compositor", notably used by the Steam Deck (in the "Deck mode"). And of course the same thing is possible with X window managers as well, Openbox seems to be a popular choice for X11 kiosks.