Are there technical hurdles around just programmatically generating a tab from any song or audio recording itself?

This is interesting and all but seems to use computer vision rather than audio processing?

Reddit r/guitar gets a lot of questions about AI generated tabs that are unplayable (the fingering is just crazy).

You need to both work out the chords and also decide on fingerings a human could perform. Seems possible, but more then just audio processing

As far as I know, there still isn’t a tool that can reliably produce usable transcriptions out of the box, although the results for solo piano can be reasonably good. A lack of high-quality labeled training data, especially for instruments other than piano, is probably part of the reason. But the problem is also more complicated than it might initially seem: you have to handle polyphony, overlapping harmonics, timing and articulation. And in the case of guitar tabs, it's even more complicated as one needs to determine what tuning is used (if not standard), which string and fret produced each note. Or separately rearrange the tab.

Using computer vision to read the existing tab from the page would be more efficient and precise than trying to use audio processing to isolate individual notes from a single instrument in a potentially busy audio track. The existing tabs also nail down which string and fret is used for each note, which would be a difficult task for audio processing because there are multiple combinations of string and fret for any given note. For example, an open G can also be played on the 5th fret of the D string, or the 10th fret of the A string, or the 15th fret of the E string.