Even if BIAB development stops today, in it's present form, I know it will entertain me for years to come. Let me put it this way...
When references are made to AI, it is like comparing a mass produced "artwork" from Walmart to a local art gallery. Sadly, as history shows, masses will prefer buying a $29.99 "wall art" from Walmart, instead of getting a $80 limited etching, supporting local artist. But even with all Amazawalmarts combined, there will always be interest and demand for "handmade" arts & music.

Sure, program needs "this & that" no argument there...
But the library, even in existing form is phenomenal. Not some chopped cuts from a 1 minute gigs that some developers call "libraries". But a true music library with thousands of hours of performances by talented humans that will play with and for you!

Of course if you got time and money to waste you can just hire anybody and do anything, but for hobbyists, backing tracks, non-gig artists, "on demand" tunes, pro-sounding sketches that can later be embellished with live musicians, substituting a drunk guitarist, bassist who is on a vacation, pianist who is waiting for a tuner, if you have no time for basement practices, need a solo part for the instrument you are unfamiliar with, I can go on...BIAB will come to the rescue. Pre-requisite is to like the genres heavily represented in BIAB: Pop/Rock/Blues/Country/Jazz/Folk