Earlier quoted context omitted.
> The house I live in was built with ethernet, but of the fourteen outlets the builders saw fit to include, not one is located where we can make use of it. I had a similar situation a few years back. It was a rental so I didn't have access to the attic let alone permission to do my own drops. It'll depend a _lot_ on your exact setup, but we had reasonably good results with some ethernet-over-power adapters.
We have them at home as well and they really suck. They lose connection every 20ish minutes at best, and take about 5 to reconnect. Makes Zoom meetings impossible, among other things.
In general they do suck, but they can be pretty decent if you stick them all on one phase, even better if all on the same breaker.