I play guitar/piano, and I concur that they’re not great. I tried “Vagabond (acoustic)” by Wolfmother. I figured it would have an easier time because it’s just a vocal and an acoustic guitar. Some of the notes in the tabs are right, but the melody is too simplistic. All of the embellishments are also missing. It’s interesting how the mile-high view isn’t so bad though. If I sat down to figure out the notes for a track no tabs exist for, this might look like a rough approximation of what I’d start with.