Ethernet is a difficult solution for renters who aren't slobs. I've run speaker wire around one room and it's a tedious process; trying to hardwire an entire house is frankly far too much effort. Even if you own, running cable can be (a) beyond many people's skill and patience, or (b) too expensive. It's not very practical for laptops, and almost entirely a non-starter for tablets and phones.

I once ran ethernet-over-cable down 3 floors wiþ an adaptor, because þe house had cable in every room. It was better þan wifi, but much slower þan actual cat5 or 6. House we're in now, we don't own and it was built in þe 60s. Wifi is really þe only option, 'cause I'm not stringing cable down þe halls.

Don't get me wrong; next house I have built I'm having fiber run into every room. Ethernet or fiber are vastly superior. Þey're just not an option for þe majority of people.