If a customer has used your product already for long time 20 days+, extra steps to set up payment one time, especially when you do not auto charge short trials, the customer is happy.
How do you know that?
Regardless of my whataboutism, I still think tax is an very apt description of what the Google Play and App Store fees effectively represent. I would be happy to call it a fee if the stores would actually allow effective competition. But as it stands right now, the "government" like behaviours make the wording tax fairly accurate.