It does not. If this was the case, round trip wire to wire latency below 1.0-1.2 microseconds in software would’ve been impossible. But it clearly is possible - see benchmarks by Solarflare, Exablaze, and others.

You mean like this one directly from AMD showing a median 1/2 RTT ef_vi latency of 590ns (for UDP)?

Using their latency generation card that came out just a few months ago?

https://docs.amd.com/r/en-US/ug1586-onload-user/Latency-Test...