PlanetScale had the same issue before they killed their free tier entirely. The problem is these companies need a middle tier that's profitable, and $5-10/mo often isn't worth the support overhead for them.

For your use case, self-hosted Supabase on a $5 Fly.io or Railway instance might actually be cheaper long-term. You lose the managed DX but you get predictable costs. Neon is also worth looking at — their free tier is more generous on egress and they have a $19 launch tier that sits between free and full pro.