Anyone use Cloudflare D1 or R2 for backend?

I'm thinking of using a server-less backend for a project and looking at Cloudflare's D1 databases for cost and scale. I'm already using it for web based projects.

I see a lot of folks reference supabase and firebase. I'm not really looking for discussion on alternatives but on Cloudflare's merits primarily.

I know there's no SDK so I'd have to build out APIs and auth myself to some extent which I'm fine with.