We need a new mode for Fırefox an extremely restricted form of html5 without javascript, call it html0.
<doctype html0>
No JS, no thirparty content, only html5+, css3+, text, images, videos, audio and other stuff.
<doctype html0>
No JS, no thirparty content, only html5+, css3+, text, images, videos, audio and other stuff.
However, even without the help of those headers, one could also have some discipline (perhaps also respect for users) and refrain from putting tracking and other undesirable things onto their website.
This doesn't seem to be a technical problem, so a technical solution - especially an opt-in one - probably won't help.
[1] https://scotthelme.co.uk/a-new-security-header-feature-polic...
It's time to develop a new independent web-zero with no sugar. Use a mode for Firefox and punish the cruft and bloat.