[burggraf]

Supabase developer here. Firebase has a team managing service uptime. Supabase has a team managing service uptime. If you self-host Supabase, you have to manage uptime yourself. You can't self-host Firebase.

Regarding lock-in, you're pretty much right here, but this is going to be true of your entire stack. If you choose to develop your frontend in React, or Angular, or Vue, you're going to be locked into that framework.

"...because Supabase does so many things..." is a good thing, IMHO. You can choose to use any or all of our product, and each piece you choose is open-source. If, say, you choose to use Supabase Storage, and you have an issue with it, you can switch to something else but still use Database, Auth, and Functions without bringing down your entire project.