The big problems with the Internet of Things so far are well known.
- All your stuff are belong to us. Everything is tied to some "cloud" service. Since the typical lifespan of a cloud service is only a few years, this is a big problem for home automation.
- Security. What security? Most of these devices can be taken over by almost anybody. Have we had the first IoT murder yet? Would we know?
- Limited consumer benefit. Being able to control your stuff from your cell phone is more cool than useful. A refrigerator with a tablet on the door isn't that useful, especially when it costs more than the refrigerator plus a separate tablet, and the tablet will be obsolete long before the refrigerator.
- Installation. It's possible to do insanely great HVAC, with windows, skylights, fans, and shutters all operating to minimize energy consumption and make the building pleasant to live in. You can even get all that stuff for your house. Now try to get it installed, configured, and maintained.
- "Connected" vehicles not too useful. Most of the talk about "connected vehicles" is about advertising or consumer tracking, or does stuff you can do now. Urmson, who runs Google's self-driving car project, says they don't need connected vehicles. They have to have sensing and sensor analysis good enough to reliably detect trouble that isn't "connected".
- Been there, done that. We've had X10 since the 1980s. Better systems since the 1990s. Nobody uses them.