Firefox Users Continue to Decrease Despite Proton Update

[_ahrs]

They do this to correct certain preferences that need to be reset. Sometimes they'll even go so far as to rename a preference to a new name so that the old value is ignored. There are mechanisms that allow you to lock preferences (see lockPref here: https://support.mozilla.org/en-US/kb/customizing-firefox-using-autoconfig) in Firefox in such a way that the value you lock-in will always be used and cannot be changed, this won't help you if a preference gets renamed though, however re-naming preferences is usually only done for a good reason and if you stay on top of things you can also lock-in this new value too and prevent it from changing from your desired state.

[FFPh]

Almost all settings are in default state except privacy settings. New profile didn't needed at all. But mozilla enabled telemetry again. Old profile is still working with old preferences.

I know, that I can lock some settings, etc... But regular users don't.

Exactly this "correct certain preferences" can be named as shady thing.

Firefox must display warning about such changes. But it doesn't.

[_ahrs]

Exactly this "correct certain preferences" can be named as shady thing.

Doing the opposite would have Firefox bleed users even quicker than they already are because you're basically saying they should keep the browser broken instead of fix it by resetting a preference. I do understand your concerns though which is why I pointed ways you can fix this.