You can look at several types in that list that don't have wall power easily or always available. Door and window sensors, which could be solved similar to older alarm systems, but have a significantly lower barrier to entry being wireless. There are convenience and accessibility benefits to allowing wireless battery-powered switches to control your devices. Wi-Fi can be an answer for a lot of these but there are battery life and coverage benefits to the mesh behavior of these networks without needing to spend a lot to expand your Wi-Fi coverage.