I guess that's part of the debate isn't it? Most things don't actually have a tremendous number of academic sources. If I'm fantastically interested in contributing an article about say, a well known jazz band that doesn't have a page on wikipedia, I may be terribly limited in what secondary resources I can call upon.

Jazz bands don't get a terrible amount of coverage in main stream media, they don't become top-40 acts, they don't get academic papers written about them in the ACM, etc. But they may be hugely influential, have tens of thousands of listeners, and may have other qualifications for why they should have a page. But if they don't meet <arbitrary person>'s requirement for notability they may flag it AfD and then it ends up working it's way through Wikipedia's impressively broken editing process where it'll probably end up deleted despite any discussion to the contrary.

Importantly, my hypothetical jazz band may only be well known in Jazz circles, having never pierced more mainstream circles. But just like a singular academic paper that no lay person has heard about, but been cited hundreds of times, this band may have influenced hundreds of other, highly visible bands.

I'm picking Jazz here, but it could be any other fairly insular sub-culture, say Blue Grass, or Model Train collectors. It's not up to me, as somebody not interested in their sub-culture to decide if it's notable. That only tests whether or not something has percolated up to "common knowledge". If that's the test for inclusion, then we don't really need Wikipedia anyway do we? Everybody already knows what's in it!