Tor Browser serves a different purpose/use-case to the first two. The first two are intended for everyday browsing while I've never heard of anyone using Tor Browser as their daily browser—and if you log into websites then using Tor Browser as your daily driver would defeat the anonymity purposes if you're logging in anyway.
I use librewolf for everyday browsing and Tor Browser for things requiring a higher threat model.
I assume that by "selfish" you mean taking up bandwidth from the Tor network, which is a valid concern. But using it as a daily driver for low-bandwidth tasks like reading text (and maybe a few compressed pictures here and there) is actually be beneficial to the Tor network, as it increases the size of the crowd, thereby making everyone more anonymous.
Yes, I think Mulvad Browser might be what people are looking for. They worked with the Tor project people and designed it for maximum clearweb anonymity, particularly in tandem with a VPN.
I personally wouldn't use it for everyday browsing, but I don't even use Librewolf for everyday browsing.