once you got the iphone backup extracted (idevicepair -> idevicebackup2 -> ideviceunback), most of the phone content is there in sqlite: sms.db, call_history.db, Calendar.sqlite, NoteStore.sqlite etc - see reincubate.com for a list.
There’s tooling around on github to transform the sql into something that can be consumed again. Here’s a sample (can’t vouch for them though), search for ios forensics if you’re missing anything