While they might be pretty mainstream now, I still think that part of the main appeal of memes is that they are seen as provocative in some way. More often than not, they’re making some kind of statement that people don’t feel capable of making otherwise. That, or they are based around an incredibly silly pun.
In short, they can often give the impression that they are here to challenge somebody, somewhere. I don’t really believe that this is true, though. Their most important function will always be bringing a sense of comfort and/or entertainment to those who are broadly open to them. In this way, they aren’t countercultural at all (never mind the fact that they were talking about mainstream memes on The Ellen Show however many years ago). Anyway, none of this has to be that deep. Just have fun mindlessly scrolling through this latest selection of memes.