Firefox, out of the box, is going to be perfectly useless to me.
At home, I have an internal DNS resolver which is used for internal stuff (e.g., Home Assistant, a friendly name for my NAS, etc). This will be broken. Likewise, I've got Pi-Hole set up for my girlfriend, but that's going to stop working as soon as her Firefox updates itself to this version.
At work, we have an internal DNS resolver for obvious reasons. All of the users who use Firefox will suddenly be unable to access internal sites. That's going to be a fun time for the helpdesk as 3000+ staff start receiving updates.
I know it can be turned off, but having to track down a hidden setting to make the browser actually function correctly is insane.
This isn’t enabled by default on any versions of Firefox and Mozilla does not have a timeline for enabling this by default on any future versions of Firefox.