Even setting up a vlan doesn’t work half the time because the mobile apps don’t talk directly with the appliance but phone home to a cloud service. A cloud service that will eventually go offline and leave the appliances orphaned. That’s how GE’s thermostats work.
I would highly recommend the History of English Podcast. This particular observation made by OP is thoroughly covered in this particular episode: https://youtu.be/T0ED-FV7O50