Back in the 2010s, EAs spent a long time dunking on doctors for not having such a high impact (I'm going off memory here, but I think "instead of becoming a doctor, why don't you do X instead" was a common career pitch). I basically mostly unreflectively agreed with these opinions for a long time, and still think that doctors have less impact compared to stuff like x-risk reduction. But after having more personal experience dealing with the medical world (3 primary care doctors, ~10 specialist doctors, 2 psychiatrists, 2 naturopaths, 3 therapists, 2 nutritionists/dieticians, 2 coaching type people, all in the last 4 years (I counted some people under multiple categories)), I think a really agenty/knowledgeable/capable doctor or therapist can actually have a huge impact on the world (just going by intuition of how many even healthy-seeming people have a lot of health problems that bring down their productivity a lot, how crippling it is to have a mysterious health problem like mine, etc; I haven't actually tried crunching numbers). I think such a person is not likely to look like a typical doctor working in a hospital system though... probably more like a writer/researcher who also happens to do consultations with people.

If I had to rewrite the EA pitch for people who wanted to become doctors it would be something like "First think very hard about why you want to become a doctor, and if what you want is not specific to working in healthcare then maybe consider [list of common EA cause areas]. If you really want to work in healthcare though, that's great, but please consider becoming this weirder thing that's not quite a doctor, where first you learn a bunch of rationality/math/programming and then you learn as much as you can about medical stuff and then try to help people."