This information can be relevant for a site that needs to know your capabilities. No need to render some canvas if your client is a text browser.

It isn't trivial to craft legislation to separate these use cases, but it also is far from impossible if there would be political will to do it.

I think the latter is far more interested in surveillance of users where tracking is one building block.

And of course legislation is needed to criminalize tracking without user consent. It would just be an internet stalking law being applied.