@nonoise so, the moderators did not like calling the guy what he is.
But either way, there are no measurements in that video, and the guy is clueless. He doesn't know anything about Ethernet at all as evident by the video.
for instance, he says all electronics are contained in the SFP, which is patently false. Open ANY switch and you will see this very clearly.
And then he says "don't use wifi unless you bought it from me". Yeah, sales guy at its finest.
Below is a link to an article describing what is in a switch, which proves that this guy is clueless. Completely clueless.
On top of that, he references a video by another guy who states why you shouldn't use wifi, and that guy "Apple TV X", correctly states that wifi has more than 10x latency, and therefore you shouldn't use it for audio. Well, it fails to account for buffering, and what the human ear can perceive. Wifi is perfectly fine for streaming audio.
In a residential setting, there is no RFI propagation through Ethernet, it is impossible. No one has ever posted anything factual to the contrary. Lots of people have posted things they think says this, but doesn't. Dunning-Kruger....