Firefox and Safari have massive hard coded lists of carve outs.
There is a colossal amount of specification work to do to figure out how to make various necessary web flows possible again after removing third party cookies.
Chrome has an incredible commitment to web standards, to not throwing in arbitrary browser-specific web functionality, to going through the process of improving the web holistically. Trying to live up to that high expectation is hard, and we can see a dozen third party cookies or storage isolation concerns they're having to tackle if we go look at https://github.com/orgs/explainers-by-googlers/repositories?...
Funnily enough, it's exactly the other way around. Google was prevented by completion regulators from turning down third party cookie support by default.
(And users already have a choice, Chrome has a setting for whether 3p cookies are allowed, blocked, or blocked in just incognito mode. Reading between the lines, they are probably going to ask users to explicitly choose, since they're not allowed to change the default.)
There is a colossal amount of specification work to do to figure out how to make various necessary web flows possible again after removing third party cookies.
Chrome has an incredible commitment to web standards, to not throwing in arbitrary browser-specific web functionality, to going through the process of improving the web holistically. Trying to live up to that high expectation is hard, and we can see a dozen third party cookies or storage isolation concerns they're having to tackle if we go look at https://github.com/orgs/explainers-by-googlers/repositories?...