> For postgres, the bottleneck was the CPU on the postgres side. It consistently maxed out the 2 cores dedicated to it, while also using ~5000MiB of RAM.

Comparing throttled pg vs non-throttled redis is not a benchmark.

Of course when pg is throttled you will see bad results and high latencies.

A correct performance benchmark would be to give all components unlimited resources and measure performance and how much they use without saturation. In this case, PG might use 3-4 CPUs and 8GB of RAM but have comparable latencies and throughput, which is the main idea behind the notion “pg for everything”.

In a real-world situation, when I see a problem with saturated CPU, I add one more CPU. For a service with 10k req/sec, it’s most likely a negligible price.