A different way to look at it might be that there are fewer applications that can benefit from higher speed that can't be parallelized. 2x speedup on your CPU gives you what exactly? And at 64gb of ram, I don't need 128gb unless I'm moving into HPC territory. Consumer PC hardware is good enough and everything new people want to see has to do with flashy graphics in low-power small-form-factor devices (or people want decisions made for them in what turn out to be computationally intensive ways).

As you point out, graphics, deep learning, AR, and others can benefit from increased computational power. Therefore, we're seeing Moore's Law (which didn't start with Moore) appear where that increased compute ability can be most readily applied.

Meanwhile, when an exciting new technology appears, there are always a small group of people that have the required expertise. With IT, young brains are able to learn these new skills incredibly quickly, so markets respond very quickly. From what I've seen, there's usually an overshooting effect where people think "there's a future in X" for longer than they should. Maybe school is to blame. But basically, you have a ton of new entrants to the market, and they fill demand, but demand levels off sooner or later, and that leads to the low-paying oblivion you're talking about.

I point all this out because there's nothing magic about deep learning, AR, etc. They may not be high paying niches for long. And already, the most-reliable/highest-paying opportunities seem to be working in small groups serving defined markets.