I'm not quite sure they're gone. He doesn't quite fit the definiton of a polymath, but Arnold Schwarzenegger comes to mind as someone who has been successful i

I'm not quite sure they're gone. He doesn't quite fit the definiton of a polymath, but Arnold Schwarzenegger comes to mind as someone who has been successful in many disparate areas. And Elon Musk has a BS in physics, co-founded PayPal, SpaceX, and Tesla, all of which are quite different from each other. Some kinds of research necessitate knowledge in a lot of different fields. My work is in molecular dynamics simulations, which requires a mix of chemical engineering, chemistry, physics, materials science, mathematics, and computer science. The school I attend even offers a minor titled "Interdisciplinary Graduate Minor in Computational Science". I think part of the problem is that people don't want someone who is kind of good at everything; they'd rather have someone who is an expert at one thing. My undergraduate advisor told me to not put my undergrad athletic achievements on my grad school application; he said it would be seen as a detriment (I ignored him). But I've often found some of the best people in their fields are also the best at many other endeavors, because it is their work ethic and perseverance that pushes them beyond whatever their natural genetic limit is, and these traits are common to whatever it is they attempt to master.