applications – How to pull app data from the phone (without root)

I’m trying to pull down app from the phone, and see the files within
First I used App Inspector to get a package name.
Then few options to get the actual apk down, but no luck.
So I”ve done

adb shell
pm list package health

so it listed Samsung Health as com.sec.android.app.shealth
Then outside the shell I tried backup

adb backup -f SamsungHealth.ab com.sec.android.app.shealth

Provided PIN on the mobile, so it downloaded but the file is tiny 500b. I tried to tar it but no luck.

dd if=SamungHealth.ab bs=24 skip=1 | openssl zlib -d | tar -x

or

dd if=SamungHealth.ab bs=4K iflag=skip_bytes skip=24 | openssl zlib -d > SamungHealths.tar

but either say that zlib error (Fedora 32, with zlib and openssl installed and tar works normally otherwise

140635897317184:error:29065064:lib(41):bio_zlib_read:zlib inflate error:crypto/comp/c_zlib.c:400:zlib error:data error

I tried other option within adb shell

adb shell
run-as com.sec.android.app.shealth

error – run-as: package not debuggable: com.sec.android.app.shealth
so I couldn’t even continue to go and see the folder

cd /data/com.sec.android.app.shealth
ls 
cp ....

to list files… I tried for several application not systemic, user installed but same issue


1.) So, Is it possible to see files of particular app at all if not rooted?
2.) Why backup so small even though each app had 150Mb + data?
3.) Any other way to open backup file, as it looks like is not a tar archive convertible?
Thanks