I have looked into this for Samsung. Same lack of interest.
They provide a tool (name changed recently, was Kies, same non-functionality) that sounds hopeful but all it can do is make a copy of the phone and restore it to another samsung. It takes a lot of manual reading to determine this. It all seems so hopeful. It ONLY works over USB and my phone data connection no longer works.
There seem no third party tools either.
I have got an FTP Server to work on the phone but ALL the current ones I tried fail because they are limited to 1024 (I think it was) bytes of directory listing. I assume this is some limit in the API.
Against my better judgement I found an old FTP App I had used previously that is no longer on the Google Play Store and that works great. I had to download an APK file which of course could have been altered by malicious parties.
This allowed access to the photos etc but the contacts are in some unknown propriety format and location.
It's unbelievable. Is it 1985 again?