But there is no point to publishing written text, if nobody reads it. It would make more sense to keep a private diary, in that case, than to expose yourself to the public.

An unfortunate consequence when people constantly use centralized, algo-based social media, over a long timeframe, to gain whatever confidence that they can't seem to gather in real life. The need for validation from complete strangers has essentially become second nature and an arguably permanent psychological need. Sad really... so many have become psychological slaves to their social media accounts and seem to be in constant competition with others. "Why does this person deserve to be happier than me?" "Well, I'll show them how much better my life is than theirs!" LOL

Or it's simpler than that. They don't need to use it to talk to themselves. They can handwrite their thoughts. Set up a private public key. Not much is happening here. I may come back some day. Bye. You can assume they are seeking validation. Or because they are not seeking validation and interaction they have no reason to be active.