I really believe that any character can become a favorite or a preferred type if the story is fun and well written and the characters can reflect their personalities without it becoming a stale, overused trope.
Strong MCs that stick to their guns and are unwilling to bend to fit ideals or compromise morals can be so!! good to read with the feeling of rooting for a hero or even the playful frustration of wanting them to change their minds. ( ◡̀_◡́)ᕤ
On the other hand, a true morally grey MC (especially f!mc) are much more rare so there are tons of avenues of unexplored stories to be able to fully flesh out a wonderfully psuedo-villain that you still want to succeed with a heavy heart. ദ്ദി˙∇˙)ว