At least in my clique in Finland, BeReal is alive and kicking. Definitely nothing like Instagram in terms of popularity, but quite active

My German circle of friends is also still very active on BeReal.

I think BeReal was too restrictive. Considering all the types of content on social media, very little of it is selfies. The goal of that platform is authenticity in a very narrow sense, which is a noble goal.

But it being too restrictive was its unique selling point, like how Twitter's limited post length was.

The "problem" with most social media is the same with F2P games: they require whales to keep them relevant

The critical mass problem is only insurmountable for social media that seeks to connect people globally. Locally, you never notice this problem.

For example, in your typical gaming clan Discord server, a tenement building's WhatsApp/email group, or a small town's quarterly town hall meeting. It only takes a handful of people in such social groups for the group to serve its purpose.

Indeed, TheFacebook easily reached its critical mass when it was limited to Harvard College. Hacker News would work just as well with 500 monthly readers as it does with 5,000,000+ currently.

Whales, celebrity influencers (whether from out-of-network or homegrown celebrities), and other such things are only needed to compete with the social media giants today. But if you don't wish to compete and want to serve a small community, then this is not a problem.