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Google's New Web Environment Integrity Proposal Dismissed by Brave, Mozilla, and Vivaldi
(news.itsfoss.com)
This is a most excellent place for technology news and articles.
I'd do what I currently do when I (rarely) encounter websites that don't work on Firefox and temporarily open Edge for that sole website, and then close it.
It's very doubtful though that websites whose goal isn't to serve you ads would bother to implement this, however. But I don't envision a scenario where browsers that refuse to implement this just become non-viable.