Comment by wowczarek

Many WiFi-based "smart" devices can run locally without Internet access just fine and are supported by HA or other such platforms, which then doesn't require you using the vendor's app, which might have you need to be on the same broadcast domain as the device. They can use multicast (few home users will have multicast routing between VLANs), or direct broadcast - meaning you will likely give them Internet access because your phone needs it - well unless your WiFi is smart enough to limit individual clients. So a restricted VLAN plus HA or some such solves this.

The real problem is those devices that actually don't let you control the device locally - Tuya being one notable example. There are thousands of products that just went and dropped in a Tuya board.

Tuya is completely cloud-controled. To control these locally you need a "local key" that is buried deep in their developer platform, and changes every time you re-pair the device, and getting it without registering the device is, on purpose, near-impossible without tricks like using an Android emulator with an old version of their app that stores the key, and even then requires effort to exfil the file out of Android. Horror. A device you physically own, only responds to control from the mothership.

So yes, you don't get those kinds of issues with RF protocols, of course unless you put the vendor's "bridge" on your network...

A friend of mine found Zigbee unreliable where he was, and just wired the home for 1-Wire. Temperature sensors, relays, heating PIDs etc. Not only it just won't die, but good luck to anyone hacking it without extra equipment and ripping wires from walls, and firstly being inside, unsupervised and undetected.