The X-plore File Manager is the only file manager app that I know of to date that has solved the post-Android 11 "Loading Error! Access Denied" problem created by Google. With X-plore, you can stay on Android 11 and enjoy the pretty new aesthetics, but also still access files in your Android data folder. I'm sure the other file explorers will catch up eventually, but right now, it's Lonely Cat Games for the win.