[skolskoly]

You might have misinterpreted me. I did not say there was ever singular in-group for the word, aside from the aggregate of all the groups that used it. The point is that the aggregate now includes everyone, and you can not have an in-joke that everyone is in on; that is just a regular joke. So, of course the appeal is lost to the people who enjoyed them for that fact.

But most people like regular jokes, and that's fine. As you suggest, "meme" began as an umbrella term, and various in-jokes will continue to be made, even without a word that specifically describes them.

The popularization of the term took about 20 years, and it looked a bit like an economic bubble: Many confused people, trying to mass produce things that are only valuable due to scarcity. Worse, it's a social phenomenon, rather than economic, so the process has been like watching a joke fly over someone's head a thousand times in slow motion.