I still have to understand why people need to control everything from their smartphone, when there are simpler solutions that require much less of your precious free time to be implemented and used.
IoT means more than just "control everything from your smartphone".
The only IoT device that I knowingly have is an IP camera in the room where our grandchildren sleep whenever they come over to stay. It is only switched on when they are with us.
It isn't controlled from a smartphone. It is accessed from one or more tablets. It is blocked from accessing the internet at my firewall. If there are firmware updates, I will download them and apply them manually, not that I expect that to happen before the sun grows cold.
The point is, IoT can mean any device connected to your local network, not just the shiny things people automatically think of. If you have such a network, then you are responsible for everything that is connected to it.