I don't think Jm is a favorite, or any of the vocal line, except maybe Jn. The hyungs have the most favor. Jn probably helped fund the group in the early years. Families often sponsor the debut and he was wealthy enough and likely has connections. Jm wasn't allowed to make a video for each song, but NJ did one for each of their debut songs and have corporate sponsors. Btees was sponsored by a discount family department store as nugus.
Jm looks like a regular cute masculine man. There's nothing gay about him, but arrrmys love to make him the self insert. If they want abuse, it's jikook. Toxic but romantic, it's Tae.kook. Protection, then Mini:moni or Yoon;min. If he's seen the fanfiction, and he has, what does he think about his fans? His pjms are all he has, because he's just a little gay boy to the rest of the fandom.
Jm can walk away and be happy. Find a nice partner or marry the one he has.start a family or grow it. The world is open to him. He should take advantage of his connections and move to the next stage of life.