One more factor to take into account with any Wi-Fi device is that you can run into a device limit pretty quickly. Many home routers can only handle up to 30 devices, some will go up to about 100 but cost a lot more. In contrast, you can have literally thousands of zigbee devices, one reason they are so popular for lightbulbs.
And of course then there’s the power utilization issue, although if you’re running the fans anyway you may not care about that as the controller is only a tiny fraction of the total fan usage.
Anyway, just something to keep in mind once you start going up above about a dozen Wi-Fi IOT devices. 