Good article.
There are not that many payment processors and they need something that has small fees, so it can be used for games that are $ 2.
I would prefer a wallet based system, as seen on other platforms. So you would pay Itch a bigger sume that could in turn be used for micro transactions. One transaction, instead of several. Itch does not even have a shopping basket, so buying two items from the same developer costs two times the base fee plus percentage, instead of one time the base fee plus percentage.