If Raft generated the same gross revenue on the Epic Games Store, Redbeet Interactive would keep approximately $111,404,038 - that's $13,236,731 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $15,055,096. 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 $88,521,394.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.