Welcome to the Impregnable Demon King Castle ~The Black Mage Who Got Kicked Out of the Hero Party Due to His Unnecessary Debuffs Gets Welcomed by the…

[sharpedoon]

Oh look it's this plot again

 

[Lunaion]

If the author actually played a mmo he would know that the classes that cheese the fight by debuffs or whatnot will be the highest demand instead of dps. Sure it is not flashy but you will always be in demand compared to the run of the mill dps main.

 

[sampahisekai]

Wait... is the author really know what he's talking about???

 

[XenonXYZ]

I think some people are misunderstanding the context of this world
This world basically has turned adventure quests into Twitch streaming prioritizing entertainment over strength. Even when people know that the the black mage debuffs would be stronger, they would prefer to watch a white mage buff their teammates. Because seeing a team fight faster/stronger/etc. is way more cool than seeing enemies just become slow/blind/etc. while the team kills them easily.
It's not about strength here, but style and popularity.