Certainly we can get the same result using Reliable sources and verifiability as we can using Notability--but that is only because we define the non-trivial mention discussion of a subject in two RSs as demonstrating notability. This shifts the burden to "non-trivial", and to "reliable". Decide what you want in WP, and we can adjust those definitions to get the result. We can also do it in a more direct fashion be defining notability. The result however can be anything we might want. Refuse to accept local newspapers, and we can get quite restrictive about people and companies. Accept a birth certificate or a certificate of incorporation as a RS, and every one of them is included.
The question is what we want in WP. There are any number of ways to write rules to get there. It's clear enough from the above discussion--and thousands of others--that there is no agreement on the basic issue of what the encyclopedia is to contain. It's not the abstract definition of rules that defines the content. The rules have been adopted and interpreted in order to limit the content.
I think there's good reason to do that. We want to do more than a paper encyclopedia can. We also want to filter the internet, and produce something that people will recognize as an encyclopedia. That still leaves a great rang of possibilities. Given that most of the people working on the encyclopedia want to include whatever they are interested in working on in whatever detail they wish to do it, and exclude whatever they are not interested in writing or reading, and limit the detail on other topics to the amount that interests them, how can we possibly achieve a real consensus?
There are some consistent approaches: to limit the content to whatever the great majority of people all agree should be included, which is practice produces a very limited result, or accept whatever content any significant number want to include, which does the opposite. There's another approach that seems rational, to limit the content to what people are prepared to write a good article on, but this produces inconsistent results, giving an encyclopedia like the present citizendium, where there are articles on scattered subjects depending on the interests of the limited number of people working there. We have more people, but not all that many who can produce a high quality article.
We resolve the situation at present by accepting inconsistency: any ad-hoc group of people prepared to give sufficient case at AfD can overcome opposition one way or another, and the consensus is the consensus of the strong and the organized. Sure, this changes from day to day, so we enshrine that as a principle.
This is managed by a self-selected editorial hierarchy, of the people who care enough and have time enough to make consistent contributions at afds and policy pages in general. But that produced consistent results only when the encyclopedia was smaller and that group of people approximately agreed with each other. What I see happening now is that the people in that earlier group want to maintain the positions they had earlier adopted; they accomplish this by adopting a rule making process that only the most dedicated of the newcomers can understand and learn to participate in, in the hope that the newcomers will adopt the old ways during their acculturation. There enough of us active newcomers now to start changing things, but no consistency in what we want, and so the old formulations tend to hold and the encyclopedia gradually becomes fossilized.