Wanted to expand on what I mean by these indie animation shows feeling like bad fanfictions of themselves:
Hazbin Hotel - Premise: A hotel that attempts to reform evil people to be good. What you would expect from the premise: Each episode is about a new guest and the main characters struggling to manage them, let alone reform them. Actual content: A grand arch-narrative about a battle between heaven and hell, with lots of musical numbers and attempts at emotional pathos that fall flat because they feel rushed and unearned.
Helluva Boss - Premise: A group of ambitious but incompetent would-be-hitmen who murder living people on behalf of the dead who want revenge. What you would expect from the premise: Each episode is about a new attempted murder plot that goes hilariously awry, as the intended victims outsmart the main characters. Actual content: A gay romance between the main character and a giant owl demon cheating on his wife.
TADC - Premise: A group of people are trapped in a virtual cartoon world and must occupy their minds with inconsequential adventures to avoid going insane. What you would expect from the premise: Each episode is about a silly scenario where the characters deal with a new monster of the week. Actual content: An extended therapy session where one character is evidently being used as a self-insert for the writer's own issues and character interactions full of "will-they-won't-they" without having already been given a reason to care.