Is there a better source and the text of the law ? Payment systems are a proxy for the fee since there isn't an explicit publishing fee. It would be quite straightforward for both Apple and Google to charge a publishing fee, which may end up close to the current rent. The larger issue is that there aren't alternative app stores. Apple doesn't allow them at all, and Google severely restricts them at the technical and…
A publishing fee would also be regressive compared to the payment tax. Right now, people don't pay until they are successful, at which point they may pay a LOT. But it keeps the app marketplace much more of a free marketplace.
I wouldn’t call $99/year “not paying.”