There's more quality ambient music out there recorded by actual humans than you can listen to in a lifetime already.
I've seen a few people discuss a desire for custom "Muzak", AI generated to fulfill a need. Upload your gym workout, and have it generate tracks to match each exercise -- right genre, BPM, type of track, right times of intensity and cooldown.
Of course you can do this with human made music in theory, but it'd be very hard to find the right tracks to match and you'd probably struggle with variety.