“I am 18+” is a well known joke as well and you can’t get purchased alcohol/weed without ID before it shows up (well, legally) because that’s when people realized they need a real measure not a fake one for show.

That the FTC would know there is no reasonable way would be a strong indicator it is indeed not a reasonable law. The default is definitely why Fortnite got fined, and is a reasonable reason to be fined, but it doesn’t make the law somehow effective it just makes Fortnite wrong for intentionally violating the law. I.e. they should have be fined but not because the law protects children effectively rather it’s not up to them to decide if it does on their own.