I agree that designations of cringe often map with the in-group(s) one associates with, but I also think there's a more universal idea of cringe that transcends group affiliations and enjoys wider consensus, the root of it being the disgust or embarrassment felt when witness to someone breaching the social contract or otherwise behaving in a way considered uncouth. Or, to draw from Erving Goffman's The Presentation of Self in Everyday Life, cringe is the aversion people feel when encountering someone that deviates from the accepted "scripts" for social interaction and self-presentation. In that sense, I think people share cringe content as a way to virtue signal that one is attuned to these normative scripts.