I think the effort in the testing of the thousands of drugs was to help create the AI model. Then they used that model and it seems to have identified a promising antibiotic. The next time they go through the process they would not need to train the model again right? So get another big list of chemicals and run them through the model.
This is a fun project, and I respect implementing anything birthed from XKCD, but I agree and don't think I'd use this sort of thing to generate my passwords. ( Or I'll just stick to Password123 )