very bird's eye view given this is a *medical* student declaring how much training is needed to be a competent attending.....
You gotta have a grip on the whole body before you focus in. Just because you've decided to become extra expert at, say, the lungs, doesn't mean you don't need the whole host of experience you gained from your 3 years with the whole body
Intern year is a totally different ballgame. A lot of people don't really feel like the world stops spinning and they pick up medicine and making more complex decisions until halfway through the year. PGY2 the first part of the year is a lot of learning AND for the first time you're supervising. Before someone says that supervising someone else's medical decision-making and leadership is only a thing if you're in academia with a residency, no. Especially if you subspecialize you always will be watching what the primary is doing and adjusting what you do, not to mention midlevels.
Lastly, PGY3 goes different ways for different folks. Some people have said by the time they hit PGY3 they're already essentially functioning at the level of attending, and the year is redundant. Good for them, I guess. I still see some value in them having a year operating at that level with someone watching.
Others, don't feel that they make that stride until later in the year. In which case, 1 year shorter wouldn't be awesome.
Others graduate an IM program and feel *barely* prepared to be practicing independently. Now, do you need to graduate feeling a fully fledged internist before being prepared for fellowship??
I've heard more from fellows saying that fellowship is challenging in a whole different way that IM didn't prepare them for. But, that doesn't really tell us the value of IM training. Other fellows have told me how glad they are to be essentially attending-level in gen IM before working on the organ system of their choice.
Also, your genius plan doesn't really take into account that matching to fellowship isn't a given, and if you don't complete 3 years in IM.... what you going to do? can't be BC. If you go with a general license which only requires a year... after you've done two.... that's not a great plan for competency either.
Also, some people (hopefully not the OP) hit a block and consult, and that's it for them. A good internist learns from their consultants. You're never going to stop needing consults, but their complexity should increase to a certain point over time.
TLDR:
It's very easy outside the specialty to declare what experience is needed, and be wrong
Each year of IM residency has its own flavor for what experience is gained
Some people, some specialties, may declare they had more IM than necessary
That doesn't seem to be the norm
How do we figure out who needs *less* training in an atmosphere where people feel like more is more??
Good internists know their limits, they also learn from their consults