While supabase could be considered a "technology" it's really more or less fancy wrappers around a postgres database. And even then, the wrappers it uses are rather well known:

- gotrue for auth, 3.2K GitHub stars

- postgREST to expost postgres as REST API, 19.8K GitHub stars

- kong as API gateway, 33.7K GitHub stars

And that still adds more complexity than just installing Postgres and creating a monolithic API