I’m less pessimistic. Even if CPUs are 10x faster than they are, that still opens up more opportunities than what can be “absorbed” by less efficient coding/masses. There will always be demands for eking out more of the available processing/compute power and doing so will always be a difficult task. For example, today you can edit large scale videos in real-time and view various movie-quality SFX applied real-time on a consumer desktop. More computing power = more ability to do things cheaply that were in feasible/impossible before. You’re limited by your imagination more than anything.
What’s truly more of a threat is AI-aided programming if that ever becomes a thing. Again, I’m not worried. The gap between telling an AI “do something that makes me $1 billion dollars” and “write a function that has properties x/y/s” or “do this large refactor for me and we’ll work together on any ambiguous cases”, is enormous. So you’ll always have a job - you’ll just be able to do things you couldn’t in the past (it’s questionable whether an AI can be built that generates programs from vague/poorly defined specs from product or even that generates those specs in the first place.
As an obvious counter example to your theory, we have CPUs that are probably 10000x more powerful than in 1980 (actually more if you consider they have processing technologies that didn’t even exist back then like GPUs and SIMD). The software industry is far larger and devs make more individually.
Technically SIMDs and GPUs existed back then but in a much more immature form, being more powerful, cheaper and widespread today than what was available in the 80s.