Medical field is under a green program. But following your point. If nursing paid more and had better conditions, it would encourage more domestic talent. H1B should be used for to get the worlds top talent otherwise it will be used by businesses to save money and depress wages.
top talent is different visa (O-1). H1B is merely specialized worker, not top tier global talent.
Nursing does pay a lot and conditions havent changed much over the years. Certified anesthesiology nurses get paid like $132/hr, and still there is shortage.
Stack rank would just give all the visas to big tech and starve US hospitals and every other industry