its just the americans tend to be cheapskates and would rather hire a few "x-years of experience" rather than the one that needs it the most entry and junior level to train them up., it saves them money,. im pretty you kinda experienced that already. tech is heading this way in the near future(biotech is already there with them mostly rejecting candidates". american ones are going to face a dwindling talent pool once the "experience one ages out/retire". plus many of them prefer visa holders over actual americans. ive done the same job search you did and its likely resulted in what im talking about. that is why some area of biotech is kept artificially shortaged , they cant have junior/fresh grads competing with skeleton crewed scientists.

plus(i think the bio job statistics are heavily skewed towards nursing, likely biotech has a much higher unemployment rate than 3.5)