because you're fighting the ad industry. The ad industry which also has their own browser and tells grandma whenever she searches about problems with cookies that there's a "better" browser out there.
Precisely. Google is an ad behemoth AND has the majority of the market of browsers. If Firefox (or Safari of Opera or etc) changes to something that breaks Google but Chrome doesn't, they'll just get more of the market. For non chromium browsers to survive, they have to play a long game and show people why these changes are important. People are happy to sacrifice privacy for convienience, unfortunately.
It's google. I'm talking about google.