As documented in the support article "Managing Data and Game Storage in Minecraft: Bedrock Edition", Bedrock Edition worlds and other files are stored at:

/Android/data/com.mojang.minecraftpe/files/games/com.mojang/

It is also recommended there that you back up worlds from there to other storage media, to prevent them from being lost, especially before loading a snapshot or beta.

After a Minecraft first time install on a new device, I have saved two local worlds, one to internal (application) storage, the other to external storage. The game is able to find and play these worlds. But the game does not create (or creates hidden) the directory /Android/data/com.mojang.minecraftpe, so it is not actually possible to find either of these two worlds and back them up to other storage media.

Because the directory is not visible, it is also impossible to restore backups to this system, making migration from device to device impossible.

Other applications installed on this device have left readable documents that can be backed up to other storage media. For example, the directories "com.facebook.orca", "com.google.android.talk", "com.imgur.mobile", and "com.whatsapp" were created under /Android/media by the respective applications, and contain visible files that can be backed up. This means Android 14 is not simply hiding application directories, making this least partly an application issue.

Two of the attached screenshots show how the local worlds list looks when set for internal (application) storage, and when set for external storage, showing that both storage locations contain a saved world. The third shows the view of /Android/data from the Files application.

Minecraft 1.20.32, 1.20.40
Android 14
Google Pixel 8 Pro