I am a guitar player. 40+ years now
I use biab primarily to build backing tracks for instrumental guitar work.
Mostly covers, a few originals.
I also use it extensively for selecting, practicing and building the repertoire.

A couple of biab features that make it great for working up the repertoire for performance.

the ability to test different styles and tracks quickly is great.
its nice to find a slightly fresh take on a well worn standard.
A reggae version of "Autumn Leaves" .... perhaps.

The ability to modify tempo is very important for learning a new piece.
You really can't play it fast if you can't play it slow.

I slow down the tempo till i can play the piece correctly 4 times through.
There is no doubt it makes learning a tune faster and correct.
It sticks better

At present I'm working on a flat-picking tune by russ barrenburg and the fingering is odd for me.
Slowing it down allows me to get the fingering right. Makes the song sound better

At a slow tempo I can begin to find little fill opportunities or experiment with the melody in sections I have down. I normally improvise at least a chorus or two in performance.

Finally the loop section. 4 or 5 tricky bars 1000 times at 50bpm till you can play them correctly.
Ok, a little exaggeration, but you get my point.

For a guitairst, expecially an instrumental guitarist, biab is the best tool I have found.

biab2023(Mac)
Logic Pro X