It's an annual collection of some of the best papers of the year. It's not aimed at the general reader so some of these will be impenetrable if you don't have a background in the specific area, but there's usually a couple of readable things in each year's edition for someone with an ~undergrad level foundation.
The numbers for active funds differ depending on the kind of fund we're talking about. For the big mutual fund complexes it's actually pretty similar to passive funds (see here https://www.fundvotes.com/). To give a bit of context someone like Fidelity International [where I used to work] is at ~70% (https://www.fidelity.co.uk/voting-record/), which is about as low as i've seen.
The point isn't that passive funds are uniquely bad, because they aren't, but it matters more because of how big they have become.
That's what you need to be true for your claim to hold water, not that the overall revenue pool is larger.