Backing up phone doesn't back up Joplin data?

Operating system

Android

Joplin version

3.2.7

What issue do you have?

Silly old me assumed locally backing up my phone would back up data on my phone (massive blunder, of course), but apparently Joplin is entirely exlcuded from backups, despite the data being physically stored on the phone, so all I got after restoring from my backup were the useless welcome notes, which I assume came from just installing the app from among the list of previously installed apps.
Why?

You weren't syncing your Joplin data or had a backup made?

As some users may have gigabytes of Joplin data, the size is likely too big to fit within Android or IOS backup mechanisms. Most mobile users probably sync, so a new phone is just a sync session away.