> That document is extremely hard to parse, and it offers absolutely no guidance wrt which parts matter the most, or, say, how the various real screen readers used in the wild behave.
No, but it does enumerate what is available which is the starting point for figuring out what is relevant to your use case.
If you want tutorials or guides relevant to your particular use case you can seek those out, but to understand them you will need familiarity with the set of available attributes and where they are or are not permitted.
Many (most?) tutorials online have flagrant violations of the specification. We need better ones that actually emphasize understanding WAI-ARIA and not cowboy markup recipe books.
> Please, stop doing this.
No, I will not stop telling people to familiarize themselves with the primary reference material. Reading technical documentation and specifications relevant to a project is not an optional step.
It is not complete in the ways you describe (actually testing real screen readers is crucial), but it is absolutely essential reading to begin with.