Rather than IoT, I'd like to have networked Things under my control. The problem is not that they're networked but that they all want to phone home to central services.
I use a few IoT devices, and have them on a non-internet network. Unfortunately it requires me looking into each product first to see if it phones home, and deciding which features I want to give up by blocking that.
May I give a "collector's" point of view? I recently added a sort of phone home functionality to an app that runs on the client's network and the only goal here is to ensure that the people who use the software get value out of it. It helps me decide what to focus on and what matters to the customers.
It's not a substitute for picking up the phone, but it allows me to have more meaningful conversations when I do so.