This is a good point, and there are ways to take advantage of this. The c++ frameworks that beat rust advertise in their repos that they are using a forked Pos

This is a good point, and there are ways to take advantage of this. The c++ frameworks that beat rust advertise in their repos that they are using a forked PostgreSQL DB driver which has been re-written to be asynchronous. There's a js framework named just-js which tops the current (nightly) DB Update benchmark on TechEmpower and I suspect they are doing the same. Additionally, Java, python, and ruby frameworks tend to gobble RAM (I work in a large corp with many deployed Java web services). This requires instances to autoscale based on mem usage or to use instances with more mem. Rust and c++ frameworks often utilize a fraction of the memory for the same service (yes, we've tested this). So we can use smaller and/or fewer tasks/instances in our autoscaling pools.