But

(a) Those things look like they need a wide berth to move around and flat terrain

(b) Those end effectors are far from universal. The payload weight seems so low that it even dropped an empty box at https://www.youtube.com/watch?v=3FIXjy2GWTg&t=150s

Well, yes, you can use a humanoid robot for that, but there are far simpler robotic solutions. There are lots of systems for handling standardized totes.