In case it helps anybody to have some options listed in one place:

capkink: alive? (and one of our off-topic anons found it, nice!) https://capkink.dreamwidth.org/1349.html?view=flat&page=121#comments

avengerkink: in limbo (closed to new prompts, open for fills) https://avengerkink.livejournal.com/21938.html#comments

mcu-kink-meme: recently revived? https://mcu-kink-meme.dreamwidth.org/820.html?view=flat&page=24#comments

avengers-kink: currently dead. https://avengers-kink.dreamwidth.org/

marvel_cinekink: currently dead. https://marvel-cinekink.livejournal.com/

guardian-kink: maybe alive? https://guardian-kink.livejournal.com/2727.html?page=66#comments

cosmic-kink: currently dead. https://cosmic-kink.dreamwidth.org/546.html?page=5#comments

gotg-kink: currently dead. https://gotg-kink.livejournal.com/933.html?page=3#comments

Not an exhaustive list, I'm sure there's more. For other fandoms you can check here (very much not an exhaustive list) https://fanlore.org/wiki/List_of_Kink_Memes