It's not only to be harder, "artificially" or otherwise. Not that vulnerability up debuffs or damage down debuffs are good for the game, but different debuffs reorient permissible means of rDPS gains and the costs of failure and who more tangibly needs to respond to them.
The first implementations of such debuffs are actually one of the rare cases where the response was pretty close to community requests. "My party members won't bother to move out of AoEs and just expect me to heal them through everything and blame me when I finally oom and we then wipe due to their negligence" led first to "This will eventually kill you, so dodge" and then to "You literally cannot fully greed this; if you don't dodge, you lose damage even if it won't eventually kill you."
The problem is that the issues should have been resolved with better learning systems and clarifications of the ToA, but that was a time of peak protection for lethargic or even leeching play (asking players to contribute would be trying to force a different play style on them and therefore reportable, but refusing to do anything would simply be a difference in play style which is kickable but never reportable") and XIV and well-devised learning systems have never gone together.
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As for cleansing mechanics, though, I'm honestly glad most damage over time effects are not cleansible, as they reduce our usually dozen+ responses and interactions between it and other damage sources... with the single and spammable "undo mechanic" button.
By all means, I'd love to see more to cleanse outside of just the Role Quests and older content, but that should be by adding more debuffs, not by shifting them to be yet more easily dealt with; I prefer that Doom and DoTs be handled by actual healing.
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Final Tangent: I'm actually totally fine with good parties with at least half of players with cross-role capacities not needing healers in fairly casual content, but I do think DPS sustain should be more pressed outside of just unavoidable boss AoEs (including stack markers). Ideally, I'd have dungeons simply and pretty automatically assign categories to each enemy action and scale those outputs, count, and frequencies with one's role composition and give non-tanks, too, a Provoke+lingering_enmity_multiplier.
Want to run the dungeon with 4 DPS? It'll require arguably more complex tanking (via kiting, splitting, and rotating who's being targeted) than when on a tank and stricter healing CD schedules than when on a healer and stricter meeting of DPS checks and dodges than in a standard comp, but it'd be doable. And with that, you reduce the forced-to-take-anyways privilege for complacent design.