Agreed. Replacing menial work with automation frees up the people doing the menial work to learn new skills and do other work. The net result is that more useful work is done, which equates to wealth created. If some of those people are incapable of learning new skills, the net surplus of wealth that we have created should be sufficient for society to cover their basic living expenses. We do not need those people to continue doing busywork in order to provide for them.
The more that we can do this, the more surplus wealth we create. This is clearly working by reference to history: this is the best time ever to be poor, compared to all points in history before it.
This isn't quite so obviously true, but it's likely also the case that an unemployed person today has significantly better life outcomes than a menial worker 100 years ago (which means mines or factories). That's what improved automation buys us.