You can now buy a Duelist, Fiendhunter, and Elder for 5 clusters each in Zadnor. Even if you don't intend to use pure essences, something like Beast + Assassinate or Ordained + Chainspell boosts your burst DPS significantly. And these items drop all the time in Bozja. Delubrum runs don't have to take 40 minutes. They can take 15 minutes if people just bothered to use essences. An Aetherweaver or Martialist can do 20k DPS if you run out of DPS essences (and Aetherweaver and Martialist are so common and are like 500 gil on the market board). Flare Star, Rend Armor, and Dervish and the pure essences also drop from within Delubrum itself.

Anyone who is not using these essences and actions are intentionally trolling the raid by making a 15 minute run 45 minutes.