I lived in America for 15 years and overall I think this is a false dichotomy. I agree with you that there is a high flying stratum that picks the elite mainly from the top law schools. (Even so, Amy Coney Barrett gained a clerkship at the Supreme Court from law school at The University of Notre Dame, which is not in this tier, and there are many other exceptions).
America is vast. Every large corporation and university has a team of in house counsel. There are layers and layers of civil servants and elected officials, with lawyers almost certainly the plurality. There is a huge number of small manufacturing firms who outsource their legal requirements and a vast legal apparatus supports this. A number of lawyers specialise in supporting construction, real estate, water rights (in the West), agriculture. And on and on and on.
I’ve deliberately omitted health specialisms, because the NHS makes that comparison unfair. But the pharmaceutical/genetics industry is centred in America and generates substantial legal needs.
I’ve also omitted the legal side of the financial industry, because I am guessing those practitioners are the stereotypical high flyers PPs have in mind.
Writing this is making me sad. It points up how manufacturing, R&D, making stuff as opposed to being largely a service economy generates all sorts of jobs. The UK was this way once.