Per a Google issue tracker thread (as reported by Android Police), installing APKs would not be so straightforward come Android 11.
On Android 10 and earlier versions, you are asked to okay an APK install, after which you are taken back to the app in question. You take off from where you left off.
Android 11, on the other hand, is governed by the Scoped Storage system. As the name implies, apps will only be given access to app-specific directories. As a result, the download process for non-Google Play apps has become a little complicated.
