Empty Notorious Monsters, Imperial Standing Notorious Monsters, Eco-Warrior... about the only thing I can think of where mandatory level caps still make some sense is the Beastmen's Seal fight "Up In Arms," and only because the number of players who'd flock to Waughroon Shrine once the level cap is removed would crash the servers. Everywhere else, the effort required to win far outbalances the rewards given.

The low-level gear has no use outside of events with low level caps, creating a circular relationship. By the time players are equipped to even think about getting on that cycle, they're already too high a level to make any use of the rewards.