I’ve actually tried this too! Had great luck at an apartment in the past, but the wiring here is also really old, and I had issues getting reasonable speed.

I need to look into newer generation Ethernet over power to see if it’d work better than the aging pair of plugs I purchased a number of years ago.

My guess is that if the power cables suck the newer generation will have bad speeds too. If you have the option buy a pair with the right to return and try it. I was very happy with this solution.