Phones should be thin clients anyway, the cloud provides the muscle. What use is packing compute into it. You just want it get smaller and zero energy use (using ambient energy for charging).
1. Do computation locally on local data, thus avoiding round-trips to a far away server.
2. Distribute an app to lots of people without having to pay for a lot of server resources to match, since the computation is done on each user's device.
3. Enable users to keep more data private, by keeping it on the user's own device.
You will still have problems with latency and you cant get way from the fact that you need power to communicate via radio your not going to be able to cut down the power that the radio needs to use that much.
1. Do computation locally on local data, thus avoiding round-trips to a far away server.
2. Distribute an app to lots of people without having to pay for a lot of server resources to match, since the computation is done on each user's device.
3. Enable users to keep more data private, by keeping it on the user's own device.