Quoting Apple, “the Accessibility Inspector enables you to identify parts of your app that are not accessible. It provides feedback on how you can make them accessible, as well as simulating voice-over to help you identify what a Voice Over user would experience”. In this video from the World Wide Developer conference (WWDC) 2019 you can watch a live demo of an app being debugged in the Accessibility Inspector, explaining how to leverage this tool to make your apps more accessible (and thus better for everyone!).
Note: a transcript for the video is available from its official page.