I generally agree that the .map() trick doesn't actually replace GraphQL without some sort of server-side optimizations to avoid turning this into N+1 selects.
However, if your database is sqlite in a Cloudflare Durable Object, and the RPC protocol is talking directly to it, then N+1 selects are actually just fine.
However, if your database is sqlite in a Cloudflare Durable Object, and the RPC protocol is talking directly to it, then N+1 selects are actually just fine.
https://www.sqlite.org/np1queryprob.html