"However, we don’t do this because it is much more scalable to drive massive machines over flat, unimpeded land."

It's just that it's cheaper since we're talking about land and other physical constraints. With humanoid robots we're talking about labor. Many processes done by humans are designed to be possible by humans. As soon as you remove the ability constraints of humans, you can design more efficient processes. This is evident is all jobs pre- vs post-mechanization.

For example, do you need lights in a warehouse without people? Do you need maximum shelf height or forklift speeds for safety standards? Do you even need forklifts if the bots are stronger enough; if not, aisles can be narrowed and density increased. Etc.

Even for in-home assistance, you might be better off with multiple smaller bots tailored to different tasks. A bipedal robot designed for cleaning gutters or shoveling snow sounds like a poor design decision.