If FlatOut 2 generated the same gross revenue on the Epic Games Store, Bugbear Entertainment, ZOOM Platform Media, Jordan Freeman Group would keep approximately $4,597,952 - that's $1,035,945 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $490,630. 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 $3,562,007.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.