Why not just make really hard content that's not exploitable by certain class stacking, and have a higher drop rate for completing it?
Or people just not spam a dungeon/boss 100 times a week, and let gear thats meant to be rare be rare. People complain about difficulty well anything is easy once you've done it 100 times. Maybe we wouldnt have to worry about horrid drop rates SE didnt know from the gate there were going to be people willing to not sleep until they beat a dungeon, then spam it all day everyday until everyone has full darklight