> Prompt engineering will never require learning an entirely new method of communication
No, but it's not like every person in the world is a super competent communicator even in their own language. But I agree the number of competent natural language communicators is an order of magnitude larger than the number of competent programmers. So I do agree with minimaxir that supply will rapidly outstrip demand, and it's unlikely that "prompt engineering" (which is a ridiculously stupid title, btw, can we still change that?) will ever be more highly paid than "real" programming (or whatever is left of real programming, at least).
Still, my point is mostly that we should be weary of making proclamations like this because it's not easy to predict how this field will develop, especially when you consider aspects like domain-specific expertise (e.g. lawyers will be in a better position than programmers to "prompt engineer" a legal contract), and the simultaneous replacement of existing jobs with AI. These factors will blend together to create a mix of incentives that makes it difficult to predict the end result.
I don't think the Assembly/C/Python analogy is perfect, but it's not far off from the truth - we see a new technology ushering in a new wave of people proficient in it, and the temptation is to wave it away as unlikely to affect the status quo, but reality never ends up being so simple.