TestFlight is a test tool that aims to make it easy to invite users to test apps and app clip experiences and collect valuable feedback before releasing your apps on the App Store. Users can invite up to 10,000 testers using their email address or by sharing a public link.
TestFlight has been particularly useful for us when we wanted to test different aspects of our apps with large groups. The ease of use made it possible for non-technical students to participate in the tests. This also allowed us to get feedback from those groups of people that we would not have been able to reach or would have had difficulty reaching with other test environments.
I have used other stores and other test software, such as the Google Play console to work with Android applications. However, I have seen that TestFLight is much more agile in the way it organizes users to be able to do the tests and the information is much more concise and directly what needs to be done. In the Google Play console there are too many sections with too much information.