Higgs isn't alone in remarking that he would not have had the time today to conduct the kind of work he did in the 1960s. Brian Greene has remarked that today’s grant-driven academia would not have allowed Einstein the luxury of a decade in which to develop his General Theory of Relativity. Eric Weinstein wrote that, "We have spent the last decades inhibiting such socially marginal individuals or chasing them to drop…
Years? a lot of great research is done as the culmination of baby steps, and papers can be published at midpoints. Even Einstein, from his patent office published at least 5 papers in 7 years. That's a pretty decent rate considering it wasn't even his fulltime job, and a PhD student working as such would probably be considered proficient(then again, I'm not aware of the paper rate of physicists).
I've met a lot more people in research who would just do nothing without deadlines than hidden geniuses that are hindered by their deadlines. Granted, I've met few geniuses too.
I'm really curious as to what task really requires years of uninterrupted work that cannot be segmented and presented for feedback.