If im being totally honest, it's the content farms that tear fandoms apart.
Like, for example:
Rainbow Friends, it has been very quiet since the content farms starts feasting on them.
FNaF, im genuinely surprised it's still standing strong right now.
Doors, AtA, Murder Drones, and countless, COUNTLESS more...
Lots of fandoms have ended up in the fandom graveyard or is severely wrecked because of content farms. (Sorry you had to hear my yap session. T-T)