It's unclear if this has any of Firebase's signature real-time capabilities.
Certainly, Supabase is living proof that there's major demand for the ergonomics of Firebase with the established SQL ecosystem; however, there still seems to be a gap of a real-time, syncing, relational data store.
That's what we are still hard at work creating at Triplit[1] while others are making strides to add this functionality to Postgres directly[2].
[1] https://github.com/aspen-cloud/triplit
[2] https://electric-sql.com/