Earlier quoted context omitted.
some of the modern software is slower because someone made a poor decision to fetch something from the network on the critical path of main functionality... kills me
It’s because modern devs by and large have zero concept of latency differences. I had to explain to people yesterday why an on-disk temporary table in MySQL was slower than an in-memory one. “But the disk is an SSD,” was an actual rebuttal I got. Never mind the fact that this was Aurora, so the “disk” is a slice of (multiple) SSDs exposed over a SAN…
Edit: It still might be a bad idea to waste the IO if you do not have to but the latency of a temporary table is usually RAM latency, not disk latency even for temporary tables on disk.