Privacy Warning Labels
While it’s not an iOS 14 feature, per se, alongside the release of iOS 14 Apple also plans to add nutrition-label style privacy warnings on the App Store so that you’ll know what kind of personal information an app will want access to before you download it, presented in an easy-to-read format.
These labels will come from developers self-reporting the data that their apps request, so it may not still be an ideal solution — a few could slip through the App Store review process with incorrect labels — but it’s definitely far better than what’s there now, which is basically nothing.