BeReal is not good (most appropriate way i could say this). It is a Privacy nightmare. Just think about it, a bunch of random strangers are getting access to every single day what you and your family are doing. I know nobody is concerned about privacy anymore. Seems like we have lost that but still Also BeReal has a bunch of Ads. And since the inclusion of Ads bereal has quickly lost in popularity. If you are searching for a Alternative, you should try out DD-DigitalDiary It doesn’t have a lot of the features like social sharing. It is basically a journaling application. But still could be a good alternative. Also there was another app Minutaie which first started this trend so i suggest you should also check it out
Privacy and social media are mutually exclusive. The ones you have linked are no exception. DD requires a phone number so I didn’t get any further. Minutiae has you taking photos and sending them to a centralized service. That’s not private. I don’t understand why you’d say that no is concerned about privacy with the implication that’s a bad thing then immediately recommend something as bad.
Privacy and social media are not really mutually exclusive - if we’re talking about a service like Facebook that follows you around the internet unless you take measures, yes. But if we mean something like Lemmy or Mastodon, it can be fine for privacy if you choose right what you do and don’t expose.