It's like if an university released an app for it's student body, they were forced to allow anybody to sign up to the university with Apple pay. And give Apple 30% of the tuition.
… that does not follow. Apple's definitions aren't based on whether a good is free. It's based on whether the service is delivered without real-world interaction by the user.
Tuition at a brick-and-mortar college? No cut.
On-demand video service with tutorials? They get a cut.
I’m zeroing in on the “real” here. Email is an indispensable service, just like paying tuition. The idea that “it’s on the internet so it doesn’t count” is... farcical coming from the biggest tech company (or one of the largest browser vendors, whichever seems more relevant) ever.