With a wifi fridge for example I can know if it stops working
You can also do that with a simple smart plug with energy monitoring. You can get a 4 pack for $35.
“not that iot device, use this one instead and get less function out of it”
You can get 4 ZigBee smart plugs with energy monitoring for $35. These are not IOT devices and if you just want to know if the fridge is running, these will do that, with the added benefit of allowing you to leave the fridge’s WiFi disconnected, which is a security gain.
The zwave alliance disagrees that it’s not an IoT platform (https://z-wavealliance.org/ Literally the title of the page calls it IoT). Also, how much power it consumes doesn’t necessarily tell you if the fridge is running and it certainly doesn’t tell you what the temperature inside the refrigerator is. Even a compressor pump zero refrigerant still inside the loop can consume power just spinning the motor.
Edit: Apparently saw zigbee and read zwave but the point stands https://csa-iot.org/all-solutions/zigbee/ (the standards body that controls the zigbee protocol).