Their App Store privacy report, as well as the app developer's explicit privacy policy, directly contradicts you. Could you kindly back that up with some evidence, or is this more FUD from you?
It uploads your usage data and identifiers (presumably username) without consent, and does so via IP, leaking your city-level location to the developers.
My information is coming directly from its app store privacy label.
Your reddit username is not your identity, and it's data which reddit already has. In fact, you can use it to browse reddit without being signed in, and reddit will glean much less data from you by the use of Apollo in either case.
The developer specifically states that they perform no user-linked tracking with their app. Their monetization model also supports this conclusion.