It is true there are so many factors and weight for each factor may differ for different medical school and hence each student should review carefully the details of specific medical school.
In any common public forum folks are going to share whatever they are familiar and hence students should still do their own due diligence and how it fits to their unique situation.
Still the UG college weight is not that critical. Especially when comparing 2 schools of similar (not comparing an Ivy or Top10 /T20 with 150+ ranked school). For example, recent thread on Baylor vs Union college. Here it really does not matter that much.
Not making a statement. But real example I have is my contact’s S went to UPenn and paid the full prices, graduated BioEngg with excellent GPA, got 39 MCAT and did research but did not get MD admission (unfortunately wait listed at 2 schools). Fortunately that kid is very successful in the non-medicine career pursued.
My D went to lowly ranked 120+ school and still managed to get MD admission. Fortunately spent only around $20-25k for 3 years (it includes $450 SW ticket for first Thanksgiving back home).
Still it is ideal student should choose a solid top UG school to explore various career opportunities and / or enjoy the college experience. But if some one is super clear on Medicine there is no harm in choosing state or any reasonable college. What the student does in that college matters.