“…the developers highlight how Android’s Scoped Storage changes will limit the emulator’s functionality. It notes that because of the poor performance of the Storage Access Framework API, game list loading times have been increased by more than tenfold. While that doesn’t affect actual emulation performance, it will take a toll on user experience. Additionally, the API’s limitations will force the developers to drop some features, like customizing paths…”
https://www.xda-developers.com/dolphin-emulator-limited-functionality-android-scoped-storage/