I use it for everyday things like schoolwork and gmail and it works great so far. I still have Librewolf on the side but it seems like it's for more privacy and that you're not supposed to change it too much for example adding more extensions or it defeats the purpose of it.
It got a big boost when Mozilla updated their ToS a couple months ago to say they could use your browser data to train their AI.
Well, it's not that they said they would, it's that they updated their terms so that they could if they wanted to. For some (myself included) that was enough.