If Microsoft Flight Simulator (2020) 40th Anniversary Edition generated the same gross revenue on the Epic Games Store, Asobo Studio would keep approximately $75,864,260 - that's $10,005,842 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $10,208,763. 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 $60,251,116.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.