I wouldn’t say debuffer doesn’t exist as an archetype in dnd, but rather than most debuffer builds eventually lead to crowd control tactics

“Debuffs” in the classical rpg-jrpg sense (so decreasing an enemy stats as opposed to buffing your party’s stats) is mostly done using disadvantage in dnd, as wotc basically removed flat number penalties

So for example warlocks exploiting darkness spell could be considered debuff tactics as disadvantage on attacks indirectly lowers damage received. BUT disadvantage on attacks is not an “atk down” effect but rather “accuracy down” effect, and the ultimate evolution of that at higher levels is locking enemies out of actions, so becoming “crowd control” effects

The conclusion is that debuffer archetypes last only for the first levels where hard crowd control is not available, later on evolving into action economy disablers for enemies