The question is: is this a necessity for doing good science today, or rather an artifact of how important research is organized today (i.e. an artifact of the bureacratic and organizational structure that you have to "accept"/"tolerate" if you want to do want to have a career in science)?

This ratio has flipped in the past 30 years, from 1994-2023, where 17% prizes were individual, 83% collaborative.

So I'd say yes, collaborative work is increasingly a requirement to do groundbreaking research today. The organizational structures and funding are a part of the reason as you mention. But it's also that modern scientific problems are more complex. I used to have a professor that used to say about biology "the easy problems have been solved". While I think that's dismissive to some of the ingenious experiments done in the past, there's some truth to it.