It's a compilation of best practices, and valuable as a one-stop-shop and checklist.

That's debatable. Every best-practice arose to solve a real problem within a context, and is only "best" if that context applies.

If you apply best-practices without a regard for that context, you end up with a dull, cargo-culted checklist of must-haves to beat people over the head with, without deriving any true human value.

The compiler of this artifact is making a judgement call[0] of what best practices apply somewhat universally (to every "decent website"). I haven't yet been convinced of their standing or judgement to make that decision.

[0]: Charitably, I'm assuming they have, rather than, e.g. delegating the judgement to an opaque model's weights.