A lot of homes are wired for power but not Ethernet, so WiFi is easier. For a couple of cameras I installed recently, I just had to drill a single cable hole fo

A lot of homes are wired for power but not Ethernet, so WiFi is easier. For a couple of cameras I installed recently, I just had to drill a single cable hole for one, and feed the power through an existing cable hole for the other - there were already sockets in appropriate places to connect them. To run Ethernet, I'd've had to run the cable through two rooms, around a fireplace and kitchen appliances, and probably have to drill an additional two holes for each camera (and ideally figure out a way to run the cable out of sight). It's not really worth the extra effort when the cameras record locally (microSD) and they're primarily a deterrent anyway.