If you target Postgres, just about any Postgres instance works the moment you enter a connection URL.
You can hop from one managed Postgres offering to another in 10 minutes and lose no functionality. Everything from auth to programming (and even RLS implemented in the query space) will work instantly: no additional software needed.
Are you claiming that's the case with Supabase and its JWT auth/RLS entanglement?
Not in my experience. The documentation and infra is just not there to make it easy to use an external postgres db.
if you have any problems, feel free to reach out to me directly. We want this to be simple (and you can see that there are non-supabase commentors in this thread who are self-hosting, so it's not just lip service)
That said it feels like every other week there's an update that breaks the self hosted compose, looking through the GitHub issue tracker shows a few issues where the suggestion is "oh yeah the latest X image doesn't work, regress the version to get it running"
I really like supabase, but stability on the self hosted images is my biggest gripe with it currently.
Supabase is one of the most portable platforms out there.
The whole stack is self-hostable and open source. All of the data are contained in Postgres. You're one pg_dump away from being able to switch to a different Postgres host. Or if you're switching to something else entirely, you can export the data to CSVs and take it anywhere. But we're confident you won't want to :)
disclaimer - Supabase employee