Zero fees for an individual, by regulation. Companies pay for PIX usage. Some banks waive these fees, and it is comparable to debit card transaction fees.
And magically things are much cheaper when you do this, both because they're actually cheaper without individual billing and associated overhead, and because the few larger payers have a powerful incentive to ensure they pay as little as possible.
Hell even the homeless people around here take donations in PIX, but you can also buy a house with it. Zero fees involved