Is that so medical professionals can break it out as a means of last resort to save a patient and ensure the course is finished?
If so that mightn't be a bad idea before we destroy the potential of new antibiotics too by having the general public misuse them render them useless over time.
Oh, and you still have to prove it to be safe and effective through years of clinical trials.
AI is basically still only helping us with the easiest parts, and this particular class is drugs is essentially a limited resource (to avoid force-evolving stains of bacteria that are resistant or immune).
At the end of the day, there's not as much research because there's a finite amount of resources to go around and there are easier / lower hanging fruit.