One OS should suffice. Driving a desktop monitor and powering desktop app features while still on battery would certainly drain battery life, so don't do that.

One OS should suffice. Driving a desktop monitor and powering desktop app features while still on battery would certainly drain battery life, so don't do that. Plug it in. The OS and apps will morph to the I/O and power class it has access to (we already have power-stepping processors... it can't be that far-fetched). Also, from this whole argument it simply doesn't follow that one OS can't scale from IoT to mega-servers. It's just code. Not all of it has to be running all the time. Not all services have to be proffered at the same time. We can do that. It may not look like "Ubuntu desktop OS on a phone", but maybe it shouldn't. That's probably the wrong direction.