The millenium was rejected for one and only one reason: the evil Rome (which was to have been destroyed) converted to chrstianity, and it could no longer play its role as the villain to be destroyed. Thus the “messiah” and the “messianic kingdom” were “spiritualized” beyond recognition, and (strangely) this is the one and only heresy which has never re-entered the Catholic Church because both Left and Right don’t want any messiah mucking things up for them.
Neither has Arianiam or Donatism or Marcionism or Montanism... it’s not the one and only