If people keep buying them, companies will keep pushing them and then claim they make up a high percentage of sales and frame it as customer demand.
Consumers need to actively reject these things.
Frankly, that's asinine. However, I'd very much like my washing machine or tumble dryer to notify me when they're done (with those appliances sitting in the basement of my house).
I even remember a dorm at uni (TU Dortmund, back in the late 90s) having a website for their washers that'd retrieve and display a status via TCP/IP. IIRC, some guys at the local computer science department jerry-rigged some custom board into standard washing machines available at that time.
Every one I've used has an alarm that goes off when it's done, and a timer so you generally know when it should be done anyway. This isn't something you need an app or an internet connection for at all.