I think what you originally said makes sense in the strictest sense. Technically, not favors. The payment was pizza.

In Frieren, the main hero would always charge a “fee” even to the poorest people who needed help. Often at the cost of totally worthless items because “now they don’t owe me”. The transaction is complete, no furthur obligation. Even “token” fees are better than ambiguous favors imo. Thats where I usually charge the friend price of a meal for most of my services.