If Satisfactory generated the same gross revenue on the Epic Games Store, Coffee Stain Studios would keep approximately $176,178,974 - that's $19,125,361 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $23,888,042. 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 $140,046,911.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.