I mean, you could use it for cloud based file storage, a calendar service, a cloud based office suite (a la Google Docs), etc. It of course can be social, but it's not entirely required that use cases all have to be. Sometimes you just want something to be easily available by more than one of your own machines from different locations. Or just to have off site backups.

Identity and self-Sovereign data. That need not be social. It can be and has been because Bitcoiners have felt the pinch more than others being censored and deplatformed from legacy social media, but if youve ever read stories about people getting locked out of Apple or Google then you realise the problem Nostr can address is much larger, not to mention entirely new things being enabled which couldn’t have worked before Nostr.