Operational concerns trumps raw performances most of the time. Stored procedures live in a different CI/CD environment, with a different testing framework (if there’s even one), on a different deployment lifecycle, using a different language than my main code. It is also essentially an un-pinnable dependency. Too much pain for the gain.

Now, give me ephemeral, per-connection procedures (call them unstored procedures for fun) that I can write in the language I want but that run on provider side, sure I’ll happily use them.