Nostr may not be on any mainstream radars as an alternative to many of these services because it lacks some vacuous sucking sound of corporate greed, containment and allure of reach to the user.
It however doesn't need that. It also doesn't fit into one category of "social app". No curated experience. No feigned freedoms granted by a solitary liable entity. Don't like the client? Don't use it. Pick one that suits you. Use a multitude of them. Build/prompt your own if you're inclined.
Open protocols are vastly more powerful than trending false narratives, censured speech, curated content, and propagandized ad revenue.
I never had to migrate from somewhere else, so maybe that made it easier, but people are sleeping on these things.
Nostr will be here when they need it.