Mathematics (or strongly mathematical subjects), music/fine arts and medicine are the only ones I can think of where it makes complete sense. Assuming you have the internal motivation.

Most other fields of study benefit from a break so you can calibrate your understanding of the world of working for a living. Otherwise it is easy to get dangerously out of touch. Especially the social sciences and humanities. The nature of the subjects suggest that experience with real humans and societies is helpful. Also for those fields, the income potential is a big issue, and it helps to get a reality check about your feelings about money and get some money-making experience before deciding whether you are willing to pay the costs of deep specialization in something like English or History.

I didn't take a break immediately after undergrad, but this had more to do with the logistics of getting myself to the US asap, which I viewed as a strategic move.

I did take a break halfway through my PhD for a year, to work at a startup, and that was hugely valuable. I was in a rut/diminishing returns from being on the higher-ed learning curve for too long, and getting on a different learning curve with rapid gains for a year helped be reboot my grad school mindset when I went back to finish.