If Demon Slayer -Kimetsu no Yaiba- The Hinokami Chronicles generated the same gross revenue on the Epic Games Store, CyberConnect2 would keep approximately $23,940,566 - that's $4,138,947 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $3,128,259. Epic charges 0% on the first $1 million in annual per-app revenue and then 12% on the remaining amount. On GOG (30% cut), the developer would earn approximately $18,948,178.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.