I think a problem might be that the jr. devs don't even get the chance to look at the code, because they're not getting hired based on their lack of experience

I think a problem might be that the jr. devs don't even get the chance to look at the code, because they're not getting hired based on their lack of experience (ref. the laundry list of advanced requirements). It reminds me of the Manager - HR pipeline, where HR people get a description of technical stuff to input in their job listings, and then proceed to gatekeep applicants away from the positions, because they don't match x % of their technical laundry list.