Why the focus on humanoid robots? Even if factories and warehouses are replete with stairs, making wheels unsuitable, I'm not sure there's a need for a human shape. Why a head? Is that to make it friendlier or something to humans it might work alongside? An R-series astromech droid feels like it's built for industrial purposes (as a close second, the first thing R2 is built for is plot). This robot doesn't need to be a human to leverage human-like hands. So is there a purpose to the shape I'm missing?
The purpose is purpose in a sense, I suppose. These aren't real products, not even close. They don't give form to anything more than vague wishful fantasies about the future, borne from sci-fi or equally vague notions of automated labor, which of course is now done by people (or animals). These are experiments and art projects and explorations and exercises. So, viewing them in that way, it makes perfect sense that they would be people (or maybe dogs - e.g. spot) - they are reflections of their function, and their function is expression, marketing, dreaming, not carefully considered, efficient, pragmatic utility.
Unless of course one is dreaming of using them to replace fashion models on the runway and in the store window. Then you gotta get those curves and moves down.