If SWORD ART ONLINE Alicization Lycoris generated the same gross revenue on the Epic Games Store, AQURIA Co., Ltd. would keep approximately $3,426,358 - that's $796,300 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $330,867. 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 $2,630,057.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.