Out of the box Firefox is definitely not very privacy conscious, better than Chrome no doubt, but worse than Brave. It can be configured to be better than both or one can use Librewolf/Mullvad browser
It makes sense. Having it configured this way breaks so many web apps that it's not feasible to have that as default. If you hope for any sort of non-technical people to use it that is and therefore to have any sort of relevant market share. Having forks with different defaults for people who can deal with the tradeoffs is a pretty good solution.