I won't enter into the debate regarding the privacy and security pro's and con's of each service, but will say there several developers offer "pro" or paid versions of their apps for free on F-Droid, vs downloading them on Aurora or the Play Store.
A couple examples are Simple Gallery Pro. and Simple Calendar Pro.
The opposite is true for other apps, like Fairmail. On their F-Droid page it's listed "OAuth was not approved by Google, etc for the F-Droid build. For this you'll need to use the Play store version or the GitHub release."