Kohler’s Smart Shower Purifies and Recirculates up to 80% of Water per Shower - Yanko Design
For a decade, the smart shower category was essentially a thermostatic valve with an app stapled to it. Not particularly useful unless you consider "Hey Alexa, switch on my shower" to be the pinnacle of smart home automation. Essentially, the water itself still ran the same path it always had: supply line, showerhead, drain, gone.