Whatever the highest-level credential is, SWEs will have a spread that’s wider than the highest-level nursing credential (and likely wider than the ratio in the entry-level SWE range as well).
I see, and you have presented, no reason whatsoever to believe that this is true.
By comparison, given the physical and time constraints of the job, an excellent nurse might be able to spread their expertise to 2x as many patients as a median? 3x? I think even 3x is a stretch. Maybe they can make a life-saving catch in the hardest 5% of cases (definitionally, very rare opportunity to apply this level of skill)?
This is why a top PI or scientist can literally save hundreds of millions (as Norman Borlaug did) but the best surgeon can save mere thousands in their life at best using surgery¹. There is a scale effect.
Likewise, SWEs can write code that can apply to all people.
Same with the top public policy people, for instance. It's the length of the lever and where the fulcrum is placed.
No nurse has that lever.
¹ I hate having to handle the edge-casers, but scientists can come up with new surgical procedures (as Werner Forssmann did) and that is way for them to use a long lever.
(Jon would have started with entry-level credentials at some point.) Substitute with Dennis Ritchie, Linus Torvalds, Bjarne S, Peter Norvig, James Gosling, Brenden Eich, rtm, rms, or whomever your idea of someone obviously on the right tail of the distribution is.
I'm sure there are famous and outstandingly accomplished nurses, just as there as there are for SWEs. My claim is that there are likely more of the latter and more continuous distribution of them.
I...disagree rather strongly that this, to the extent it is true, differentiates SWE from nursing. Comparing workers with identical responsibilities, the same is true in SWE, in both cases there are large impact multiples possible within the field, but they come from roles with greater responsibility; in nursing, because different roles require different credentials, this is reflected in the fact that a more competent nurse will be more likely to take on a more responsible role within the same credentialed category, and also be more likely to acquire greater credentials over time compared to a less competent nurse. “Nursing” isn’t a binary credential, but a whole set, starting with a basically heirarchical set: CNA -> LVN/LPN -> RN and beyond that various Advanced Practice Nursing credentials.
SWEs likewise have wide variety of scopes of practice and responsibility, but because we have no structure in the profession, they are assigned ad hoc and even with common titles there isn’t consistency in substantive roles, skills, or qualification. But, again, that’s a product of the absence of structure and credentialling, not an argument for it.