I am kind of taken aback by the growing wireless frequency clutter and was wondering if there are any smart plugs or other home automation devices that are controllable by just using the energy lines - like powerline. I mean you already have a rather reliable cable connection - why not just use it?
Sounds like someone misses X10 smart home devices. You can still install it today but the protocol from the 1970s is rather dated.
There are limitations with signals over power lines including some problems communication across circuits in a breaker panel, or signal leaking out to neighbors through the main power grid. These can be remedied but there are probably reasons why X10 isn’t in high demand these days. https://en.wikipedia.org/wiki/X10_(industry_standard)