I'd rather penalize the application than the technique. Windows was rumored to long have "quirks" that would do better things for apps that had bugs that the OS ended up fixing instead of the app.

Javascript systems have long had polyfills for varied browser feature comparability gaps.

Whether you agree with these, making probing detection via fingerprinting illegal would take away this lever. Making surreptitious tracking via fingerprinting illegal? Even for state actors?

Yeah, that's probably reasonable. If someone is going to wear a tracking collar in exchange for "free" services, a little disclosure makes sense.

I don't think it'd be possible to define fingerprinting narrowly enough to not also outlaw perfectly normal and legitimate usecases.

Why should it be illegal for me to recognize the way you walk into my store, even though you're wearing a mask and a trenchcoat? Some vague sense of indignation?

Yeah, tracking bad, I get it, but are whatever damages that kind of legislation would prevent (probably nothing measurable) really more important than fixing the easy, in our face social problems that politicians could instead be focusing on?

Why don't you ask browser developers to stop adding features helping fingerprinting? Browsers even have some API for tracking ad clicks (attribution API or something) and user interests tracking API which nobody of the users needs.