Yeah, software support tends to be pretty bad for their devices, with few updates, and they are often bad with posting kernel source for their devices, so hard to get custom roms or flash alternative OS’s on them too. But if you want a phone that has a battery that can last 3 days straight - they are indeed available for purchase
I like Librewolf a lot, and do use it sometimes on desktop, but they do not offer a mobile version, and there have been a few web pages I have found it was not compatible with.