Right, thanks. But this can be easily resolved by:

• Removing devices’ access to WAN, which also vastly reduces the external actor’s ability to compromise them in the first place.
• Isolating devices from each other with internal firewall rules, allowing them to only interact with the hub host. Is this correct, or am I missing something?

What kind of disaster specifically? I hear everyone discouraging from using WiFi for home devices, but never understood what the actual risks are.