Epic CEO Tim Sweeney previously revealed that the company pays a flat fee to each developer to give away their games, rather than paying per download.

https://www.theverge.com/2021/5/4/22418782/epic-games-store-free-games-cost-apple-trial-arkham-subnautica-mutant-year-zero

Your download doesn't give the developer any money. The fee is already paid. The Developer gets just as much from you if you pirate their game, or more if you go purchase it on a different platform instead.