How it works instead:
1) Apps that are on the Google Play get re-installed. F-Droid? Russian banking apps? Unlucky!
2a) The half of the data gets copied, the other half doesn’t. You can’t figure out which is which. You need to open each app and look for yourself.
2b) It doesn’t matter if the app gets reinstalled or not; its data *may or may not* be there.
3) Only the ‘standard’ folders (‘Pictures’, ‘Downloads’) get transferred. Other folders that I’ve deliberately put in the root don’t.
My alarm clock, ‘Sleep as Android’, got transferred with settings. My authenticator, ‘Aegis’, didn’t get re-installed, but kept its data. My habit tracker, ‘Loop’, neither got re-installed nor kept its data. Most apps got re-installed, but lost their data and settings.