They are only pro developer because they aren't breaking into the market well at all.

I guarantee that if they ever have a breakthrough and start approaching 40% sales or more, they will double their cut for sure.

Their cut is literally only to draw in developers and operate at a loss, subsidized by other income or investors, to gain as much market share as possible before jacking up prices.

It is the exact scummy playbook that amazon went by to drown their competition with their bare hands. The only difference is that Epic doesn't understand the market at all and won't commit resources to improving their store.