[antonyt]

It really doesn't have to be. Your standard zigbee smart lightbulb, for example, behaves exactly the same as non-smart lightbulb - you flip a switch to turn it on and off. You have the option of integrating it with automations and services fully under your control and even disconnected from the broader internet, if you like.

Building up a "smart" home where you have control of everything is radically different from off-the-shelf IOT crapware that turns into a paperweight when some company decides to pull the plug.