Did demand for programmers go down in the transitions from pure binary to assembly language, and from low-level languages to high-level languages?

It just became more feasible to build profitable products/services that solve larger products, which would increase the demand for programmers. As long as people/companies want to make more money, they will keep moving on to more ambitious projects that have just become technologically/economically feasible. In aggregate, they will not stop at the previous technological/profit level, downsize by firing all but the absolute minimum of programmers, and stay content with their stagnating income.

Business expands to the resources available. One programmer can easily deliver a basic website that worked great in the early 2000s, but same website won't cut it today.

It's not about "more", it's about accessibility. If AI makes creating software products more accessible, the demand for programmers will increase.

If programming was niche and hard to capitalize on then yeah the demand wouldn't increase if you could do "more".

HW engineers seems like a good example of this. HW has gotten tremendously better, but HW engineers haven't seem a commensurate increase in demand.