Allow me to add another
Averting the usual reasons for the whole "banishment from the party for not being awesome" cliche, is that MC is banished from the party for not LOOKING awesome.
the setting is not your typical fantasy world. There is no war against the demons, and no real danger of any kind. It's an Urban fantasy setting where "Heros VS Monsters in Dungeons" is more of a professional sport than anything with systems set so no ones lives are in any danger. Adventurer parties livestream their exploits for views and seek to become the most popular party.
which is where our MC has a problem as his Black Mage abilities are invisible debuffs, so he doesn't look good for the camera and the potency of his spells are hard to verify for the outsiders, so he gets the boot for another who would look better for the audience and take that number 1 spot (they are already VERY highly ranked), or so they hope. Notably, the "Hero" remains on good terms with the MC from start to finish.
MC's fangirl then finds him and gets him a new job.....the Staff Officer for the Monster side of things where his debuff abilities now make absolutely unfair dungeon runs.