People do that with phones. Given that humanoid robots are very early in their development cycle why wouldn't they need to be replaced physically? Joints will

People do that with phones. Given that humanoid robots are very early in their development cycle why wouldn't they need to be replaced physically? Joints will need replacement, lubrication, other maintenance. Same with motors, so why not replacing power/battery as part of a part? It's not about making them "thinner". The idea is that they are human sized, because they're designed to operate in human occupied areas. The first places are going to be like Amazon warehouses doing pick and pack because of the speed and all the variations of boxes and packages. That's a relatively controlled environment, they'll evolve from there.