Needs to be smaller than that and portable energy sources are the main bottle neck still in regards to reducing the size of computers. Best we got is carrying a battery the size of a suitcase that can charge using solar panels. Idk how we can make energy sources smaller than that. I hate being dependant on the electrical grid.

And if you want to travel they limit the battery size on planes that you can bring for safety reasons. So there's still a lot to figure out in terms of energy sources for portable devices of that caliber.