The main thing that I think holds Doom Desire back is its typing. Many pokemon that struggle with pokemon who are weak to steel like Clefable and Tyranitar also struggle with other non-steel weak mons. The prominence of the water typing means anything that can't break through water types can't gain anything major from Doom Desire, and any special-attacking threat looking to profit will often fall flat against Blissey and Slowking-galar due to their sheer special bulk.
Examples:
Garchomp and Dragonite struggle with Clefable, but they also struggle with Corviknight unless they're running Fire Blast
Spectrier struggles with Tyranitar but it also struggles with Blissey, and if it's a special set that can beat Blissey it won't be able to feel the effects of Doom Desire
Regieleki also benefits the same amount from Future Sight coming off a much better mon in Slowbro (who has the same Special Attack stat as Jirachi)
In general Doom Desire often doesn't have the type matchup it needs to differentiate itself from Future Sight, since Future Sight hits Pex super effective and has a lot more synergy with mons like Fighting types who need help versus Pex, and who can blow through most special walls and resists like Corviknight. Slowbro being an amazing pokemon outside of Future Sight doesn't help Doom Desire's case, either.
