Earlier quoted context omitted.
It's nice that you don't have this problem with the apps that you use, but others do.
Can you give an example? An app that doesn't back up data that's essential to you?
The problem is that when a new or wiped device installs those apps again, they won't have any of their account or configuration data. Even with a password manager to help, logging back in and configuring my preferences is a tedious, all-day affair. In years past, there were ways to transfer account data, but they stopped working a long time ago. I am eager to find a solution to this that works without root and on modern Android.