Supabase has not been abandoned; it is actively maintained with recent releases and a large contributor base. This platform remains a key player in the Postgres development ecosystem.
Supabase is developing features comparable to Firebase using open-source tools, making it a strong choice for developers looking for a robust and scalable option. You can view the project here. Given its active maintenance, diverse contributions, and consistent updates, it is safe to say that Supabase is a reliable choice for your development needs.