That exists, but it’s expensive because of the electronics and mechanics involved. There are so many interfaces with this exact problem.
You also almost certainly don’t want non-deterministic hallucination prone AI controlling physical systems.
If you want the shower to save your temperature preferences and start automatically, there’s no reason to build in a computer capable of running an AI.
But in reality you almost certainly don’t want a system like this because you don’t want an AI accidentally turning on your shower when you’re not home, when you do ok to clean it, or grab a razor, or when your toddler wanders in.
Granted an AI could try to determine intent, but it’s never going to get it 100% right. Which is why for physical systems like this you almost always want a physical button to signal intent.
Also that sounds like an awful lot of computing power for everyday UIs. It also doesn’t solve the non determinism problem.
There’s no way to use fewer actuators, and the control system is already dead simple, and uses one temperature sensor per outlet.
Who knows, AI can come up with simpler or cheaper solutions that did not cross our mind. I would say, time will tell.
The lack of AI isn’t what’s holding back your dream of a temperature controlled shower in every house.
When taking a shower, I would like fine control over the water temperature, preferably with a feedback loop regulating the temperature. (Preferably also the regulation changes over the duration of the showering.)
Choosing to read the NY times indeed is only a few taps away, but navigating through and within its list of articles is nowadays done quite fast and intuitively thanks to quite a lot of UI advancements.
My point being, short sequences are a very limited set within a vast UI space.
People go for convenience and speed, oftentimes even if there's some accuracy cost. AI fulfills this preference, especially because it can learn on the go.