External Memory Alternatives

In older versions of Android, I used External Memory as an intermediary in transferring app-specific files from one device to another when the user changes devices. That method no longer works in Android 29 and above, and Scoped Storage has been suggested as an alternative. Is that really the best way to accomplish what I want? Would some form of cloud storage be better for that? I really don't need External Memory except for this one purpose of moving app-specific internal files from one device to another - for the same app. If Scoped Storage really is the best solution, where can I find a good detailed example of an implementation that does this?