Good complete backup solution?
I usually just export my contacts and my internal storage. For more you might use the shell (and where you can choose your preferred file explorer) and copy the files you need to your desktop/laptop pc/external SD card. (app data for example needs to be copied with adb, so you have to use the shell) If you have some apps you can not reinstall, for example if they are not on the playstore anymore, then you can use an apk extractor, I prefer the one from F-droid. If you want to make a custom recover like backup you might want to look up how twrp does it.