So do you see some IOT tech that could spread without needing a router in every home ?

BLE + WiFi in some nodes; BLE in all the really low power ones that need to give you data -- like motion sensor.

I only need a bit to turn a light on, so we may be onto something here.

Dimmers need a few bits, probably 8+ for decent control. Waiting a few seconds for a light to dim would be rather annoying. Doing RGB effects would be even slower. Ovens need at least 10 for a decent temperature range. Authenticating a door lock would require at least 128 bits one way, and another 128 the other; 30 seconds would be way too long for that purpose. Plus, you need to take into account addressing, a protocol for the type of message, and other aspects in order to route commands to the proper node. 10 bits per second just isn't going to cut it.

If I'm 50cm from the door, there no need to use this protocol. This for the times you're not at home, but somewhat close.

If I want to turn the lights off and I'm at home, I just flick a switch.

You forgot about security.