You could certainly get help that was 'mechanical' but which did not involve machines or robots as we think of them today. More of an older, original definition of robot.
Directly to this thread, nobody is claiming they didn't use tools. The question is specifically why they never invented a specific tool. My specific question is why the cart wheel needs to be a prerequisite to a spinning wheel.
The common answer is that you don't need carting wheels without drafting animals. My question is why does that preclude pulleys and spinning wheels? They seem they should be unrelated.
Pulleys, in particular, seem an extension of levers more than of carting wheels.
Considering the large stone structures and pavilions they built, they sure could have used a wheelbarrow.
Their "roads" were impassable by wheeled vehicles, but I suspect that passable roads were a consequence of wheeled vehicles, not a prerequisite.
Thinking more on it, I confess the "they had wheels in toys" is actually more confusing than not. I would think it common for toys to mimic non-toys.