I have been in IT services for 20 years; my understanding is that data arrives intact or doesn't. If you hear a difference, you have a bad power supply in your switch that adds noise, affecting the DAC's Analog out. Wall warts = noise, but a good power conditioner should make all that moot. Confirmation bias is real.
I liked reading those EE's or just being well informed of us list out the inner spec on 802.x etc. Thank you.
We regularly swap out ethernet cables with systems that start to get buggy random packet loss or slowness in a database, and It's cheaper to do that than buy a Fluke networks qualification tester. (Though we have one) CAT5/6/7/8 takes a beating over time, and getting the higher-spec cable should help in inference-based packet issues.