Apple currently charges 15% for <$1m revenue. Yes, 30% is pretty standard, however they're also asking you to give up your IP. The open source only policy makes

Apple currently charges 15% for <$1m revenue. Yes, 30% is pretty standard, however they're also asking you to give up your IP. The open source only policy makes no sense from a business standpoint. Their justification was so the software can be vetted, which is nice for the user, but precludes any developer who has actual proprietary tech (in my case, GPU algorithms, etc.) Add to that an inferior knock-off of the macOS UX, a half-baked programming language they want you to use, and it's not exactly a winning combo for a developer. Instead of being purists, they could have highlighted the open-source apps in their store with a badge, giving the user a choice. They could have used say Rust or Go instead of inventing their own language. They could have better differentiated their design from macOS.