A lot of this really hits home. Some of my personal observations across residency and practice:

1. There are some attendings who have a subconscious inbuilt assumption that there are "good" residents and "bad" residents and that any team will contain a mix of both, even if it's a team of just two residents. God forbid that you should be just a "good" resident paired with a superstar resident, because then you are the one who must get the "bad" label by default. If this happens early enough in residency, it may be the first piece of feedback that your program director gets about you, which puts you at risk of being labeled "bad" by the program at large and finding yourself being pushed towards a remedial track. I feel that residency programs are shockingly bad at identifying which residents actually need remediation. Residents with serious knowledge or work ethic issues can get ushered along through the program, while very bright residents who don't understand how to play up their own successes get put on remediation plans.

2. More generally, confidence is often misinterpreted as skill, and introversion is often misinterpreted as a lack of skill. Many attendings are shockingly bad at differentiating the two.

3. Departmental culture has a huge effect on residency education. I trained at a busy county hospital and now practice at an ivory tower type place. Much to my surprise, I think the EM program here (which gets residents who were the cream of the crop of their med school classes) does a worse job of treating patients than the county hospital (which failed to even fill its residency class a couple years ago). The difference, at least in my view, is that attendings at the county hospital were extraordinarily hands on, which taught residents that a "normal" ED physician is extraordinarily hands on. As another example, the ED at my current hospital is very aggressive with CT scans, to the point that probably 20% of the patients that I admit have been panscanned (CT scan from head to pelvis). I attribute this to attendings here being more risk averse in cases with a ~1% possibility of malpractice. And it trickles down to the residents too, because again, that's what their reference for "normal" is.

4. Basic science education in med school is a joke and needs to be overhauled from the ground up. As it stands, 1st year is "pure" basic science, 2nd year is learning about the library of various diseases, and 3rd year is learning how to treat those diseases. I still remember reading the nephrology section of my 1st year textbook, a large chunk of which was a breakdown of why cystatin C is a better indicator of GFR than creatinine and a description of a procedure in which contrast is injected into the renal artery and sampled at the renal vein to measure true GFR, worked out step by step with mathematical equations. What was never mentioned: What the hell is GFR even used for anyway? Why would someone want to measure it? These pieces don't fall into place until 2nd and 3rd year.

Imagine if you learned symbolic algebra in 3rd grade but the concept of a word problem wasn't introduced until two years later. That's essentially what medical school basic science education is.

The faculty who design med school curricula are not blind to this issue, but their attempts at fixing it are laughably bad. There is "case based learning" where 1st year students are told a vignette about a hypothetical patient and are asked to generate a differential (a list of possible diagnoses) before they dive into the basic science component. This turns into a comedy skit show because 1st year students barely know any diseases, they are only vaguely familiar with the symptoms even for the ones they do know, and they haven't had much, if any, explicit teaching on how to generate a differential.

Why not take a more vertical slice approach to teaching? Introduce a limited number of bread and butter diagnoses in 1st year and gradually layer on rarer and more complicated diseases in 2nd and 3rd. Put more weight on the basic science aspect in 1st year, put more weight on aspects that require knowing a large number of diseases (like generating a differential) in 2nd and 3rd year.