A non technical domain expert might usually lack thought clarity. They might know what is right once they see it but they seldom know how to reach there, even with AI. They will write themselves into slop in 3 days.

The real moat I believe is the ability to hold the the problem in the head, isolate it and mentally design a way to structurally solve it iteratively.

Very few people have it. Much less common with domain experts.

I would rather bet on educating domain to the engineer than teaching a domain expert to architect software.