... Uh... This doesn't seem that objectionable. It's a bunch of targeted fixes to websites, I imagine every browser does it in some form. Firefox at least allows you to turn it off if for some reason you wanted to.

BTW, I think Proton (for playing games) does this as well.

Also, Every site FF pretends to be a different UA on is artificially reducing FF market share data.

Ehhh... I think a bigger effect on FF market share statistics is probably all those privacy addons and settings everyone is using.

There are so many legitimate things to complain about with Mozilla, why do people go out of their way to complain about the most innocuous shit.

Don't even get me started with about:config

Looks like compatibility hacks for various websites.

Interventions - are deeper modifications to make sites compatible. Firefox may modify certain code used on these sites to enforce compatibility. Each compatibility modification links to the bug on Bugzilla@Mozilla; click on the link to look up information about the underlying issue.

User Agent Override - change the user agent of Firefox when connections to certain sites are made.

https://wiki.mozilla.org/Compatibility/UA_Override_&_Interventions_Testing

Those are special measures to not be blocked by those sites etc..

While I agree it sucks, because it doesn't fix the problem at the source (the site causing it) and therefore reduces motivation to even do so, it makes the web more accessible for FF users, quickly.

Pretty sure it’s always been like this.

The web is a mess. If you do anything on it on any combination of software and hardware and expect security or functionality you’re barking up the wrong tree.