I’m thinking about resetting my phone to see if it fixes a mobile data download issue.

I want to avoid losing important data and also avoid cloud services for backup, as much as possible.
So, how should one ideally go about it?

• I can directly backup all files in /storage/emulated/0
• I can backup contacts as vcf
• I can backup apk’s using apk extractor
• I can write down saved passwords in Chrome and Firefox
• Create backups from apps like Pipepipe and Mihon. And also get the database file from whsap

Is there a way to save preferences for apps without root?
Are there foss or offline apps that simplify this?
Also is there a way to locally backup google calendar?
(Fossify calendar seems to have an export local calendar option. The backup file seems to be supported by google calendar too.)

Are there other things that I’m overlooking?
Would like to get suggestions/advice on this.
Thanks in advance.