If FIVE NIGHTS AT FREDDY'S: HELP WANTED generated the same gross revenue on the Epic Games Store, Steel Wool Studios would keep approximately $8,378,811 - that's $1,809,302 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $1,006,202. 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 $6,569,509.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.