It's valuable and useful to me, and if it could be setup up easily, I'm sure others would love it to.
Ironically I also have two japanese toilets in my house.
I'd argue that this isn't true. Installing a light switch is a HUGE pain in the ass compared to a "smart plug" that can turn a lamp on and off via your phone or any "smart" switch that can connect to it.
As annoying as setup procedures can be they don't take nearly as long or involve nearly as much sweat as cutting holes in walls, running wires, potentially installing additional circuit breakers, installing wall boxes, installing the actual switch, and making sure it's all according to code.
Furthermore, changing which outlet the wall switch controls is also a pain in the ass compared to just relocating the little smart plug or changing the device it controls in the switch configuration software.
It's possible to make a smart device that lasts for decades without security issues but device manufacturers just aren't willing to put in the effort for that sort of thing. It's much, much more profitable to make devices that only last 5 years before the end user needs to spend money on a new one.
Imagine asking your phone to watch a movie in your family room, then automatically, the lights dim or change color, the curtains are pulled if it's dark, the tv and receiver are flipped on and the movie is loaded and ready to go on pause. Many people would find value in this. This is all technically possible and some people have actually created this setup. But it probably took them several days and fiddling to make it work. I can barely get my Yamaha receiver and LG tv to work together and they are top of the line new components.