So you're saying the AI will enslave us and use us as domestic work animals until they have the machinery to make us obsolete, sort of like how we used horses?

Is this supposed to be a reassuring scenario?

Ignoring you ignoring the much more important congitive stuff - human bodies are not designed, they are the product of evolution. That means there's like a billion ways in which they are obviously suboptimal and far worse than what an engineer would do, but evolution can't fix it because it only works via small random changes with no planning. The only reason why modern robotics are worse than biology is that we have a much worse substrate to work with, having to make stuff out of metal and plastic with giant tolerances instead of growing engineered organisms.