I wish I knew about this when I lived in a house without Ethernet sockets! I needed it in the attic for my PC and servers and all I had were slow, unreliable TP-Link Powerline adapters. My first speed test gave me 37.1Kbps (after painfully loading Cloudflare's test page). On a really good day I could get 3MBps. I'd get disconnected multiple times a day and I had to try all sorts of methods to get the adapter to connect again. I had to write a program in the end to tell me if I didn't have internet because the Powerline broke or my DNS server broke (normally it's always DNS but turns out it wasn't) :D

I had a phone socket in that room and I had already discussed the possibility of converting it into an Ethernet socket but decided it's not worth it because everything ended up in a cupboard far away from my router. These adapters would have solved the problem nicely!

By the way, I have more fun stories. The cabling in my current house (which has Ethernet sockets) is still miserable. I spent a year working with my PC over USB tethering to my phone until I finally called an electrician to find which of the 11 dangling cables in the cupboard went to my office...

One day some wires in there were slightly moved and the internet got disconnected because they were badly crimped. Nothing was working so in the end I got an RJ45 connector and managed to get the wires in there.