Besides the other use cases that benefit others have mentioned, there's much more to perf than req/s for a webserver.

Basic examples:

- Latency/processing (which suffers as req/s grows or peaks)

- Memory usage (idle, at peak)

- Startup time (one-off jobs, serverless cold boot)

The "thousands of req/s" benchmarks are often unrealistic - either super simple (the benchmark you linked serves a static tiny JSON payload) or hyper optimized and not representing a run-of-the-mill webserver.