You're missing the whole point of IOTA - being that it can be utalised by IoT Devices, if you added a POW that required an increasing difficultly the small IoT devices wouldn't be able to keep up with the demands.
You're missing the whole point of IOTA - being that it can be utalised by IoT Devices, if you added a POW that required an increasing difficultly the small IoT devices wouldn't be able to keep up with the demands.
RE: IOTA: Replacing the Centralized Coordinator with 1% Annual Inflation