Yes we'd be better off if cookies were removed.

But if it was only Firefox, people would simply add banners saying "Firefox is not supported." since it's only like 3% of marketshare these days.

You apparently missed the entire point. My point wasn't that one browser would/should do it, it was whether this whole moral outrage at companies using it could ever generate a plausible scenario where we as a community decided to not allow it and actually enforced it (aka why I said Firefox "could at least make a stink about it"... which they haven't nor has any serious tech privacy group called to block cookies wholesale).

If we are going to allow such a system then there will be natural consequences. These cookie prompts are a fools gold security theatre solution that has done nothing to improve privacy. Yet it has geneatred a mountain of UX annoyances since every single one is designed different.

Likewise blaming companies for using a limited set of cookies (see: not supercookies) is silly. There's a million legit usecases and the alternative of banning cookies is not a real solution. Stopping fingerprinting is a whole other issue.

Suggesting otherwise re: cookies is disingenuous.

Browsers can't tell if a cookie is a generic setting ("chose Yes/No on a banner") or a uniquely identifiable one; and they can't tell if a cookie is functionally required (ID for a logged-in session) or not (ID to track random visitors).

The distinction is legal, not technical; so it has to be enforced by legal, not technical means.

Firefox COULD default to cookies off (with an in menu widget to force them on for non-automatic handling), and if any forum submission happens _ask_ if the end user wants to accept the site's cookies.

Looking at a typical site, a reasonable user might want to accept one (or perhaps a couple) of many dozens of cookies a site attempts to set. Choosing it manually per site per cookie is difficult but perhaps theoretically possible, however even that still requires cooperation from the site to honestly identify that this one is the cookie which is functionally required, and these fifty are for ad tracking, and ensuring that cooperation still requires legal means and can't be done with purely technical ones.

Furthermore, there is the important distinction about multiple uses of the same data. There are uniquely identifiable cookies that are functionally required for one purpose but the site may want to use it for other purposes as well (e.g. share that data with heir "trusted partners" for targeted advertising) for which user may reasonably want to refuse permission, so a browser accepting a cookie doesn't imply such permission and something extra is required.

I think when you click "accept", you also accept to things like fingerprinting and storing a fingerprinted identity on their server, as well as perhaps supercookies, that allow your ISP to track you.