> In the UK at least, researchers have many options for research fellowships of 3-5 years, paid, many with total academic freedom to do whatever you like
Perhaps in theory. But surely you're not going to get the next fellowship (or other academic role) unless you have shown some demonstrable output at the end of this one? That's still at least some level of pressure to try something safer but incremental rather than risky but potentially groundbreaking.
You wouldn't get 5 years to noodle -- maybe 1 or 2 at best. You're competing for your next thing against other smart folks who are going hard on maximizing publication rate and grant winning in their current thing. To continue with your riskier, bigger thinking you'd have to be ready to bet that: (i) you'll produce a highly impactful result before you start applying for your next thing and (ii) the high impactfulness of that result will be recognized in time to support your applications.
The most successful folks tend to mix talent and hard work with a bit of luck in terms of early gold striking to gain a quick boost of credibility that helps them draw other people into their fold (eg, grad students in a big lab) who can handle a lot of the metric maxxing to free up some (still not enough) time for more ambitious thinking.
Perhaps in theory. But surely you're not going to get the next fellowship (or other academic role) unless you have shown some demonstrable output at the end of this one? That's still at least some level of pressure to try something safer but incremental rather than risky but potentially groundbreaking.