As a seller, you understandably want that valuable buyer info.
But as a customer, I'd deliberately avoid Paddle to keep my privacy and avoid spam. If anyone thinks that Paddle's 10% fee might mean the final in-app purchase price would be lower which would make it worth the tradeoff to give my data, I'm not so sure about that since an interpretation of the ruling still gives Apple the right to get 30% via Paddle: https://9to5mac.com/2021/09/14/apple-can-still-charge-its-ap...
If anyone thinks getting a % of someone else's payment stream is unusual, consider how the "360" record label deals[1] with musicians are structured. All the musician's revenue (CDs, streaming, t-shirts) regardless of payment method (box office or website selling tshirts) is split with the record label. Why is that "unfair" situation even possible?!? Because the musician signed a contract agreeing to the revenue split.