If BeamNG.drive generated the same gross revenue on the Epic Games Store, BeamNG would keep approximately $102,217,670 - that's $12,401,606 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $13,802,410. 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 $81,214,056.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.