You sign up for a product. No email is requested/provided.

You might later want: - to submit a support request and receive a response via email. - to get blog posts or product updates in your email. - to receive a transaction receipt

Trust is earned over time. I would much rather grant granular scopes as a product builds trust.

Even from a user standpoint... oops I clicked the "cancel" button when I meant to click "confirm" and now I have to go through the signup process all over again because the developer is not allowed to ask me again.

Last time I touched permissions the app was able to give the user a link to iOS Settings page where the user can grant previously denied permissions.