Perhaps you would care to explain how bacteria developing resistance to specific antibiotics over the course of thousands of generations is a result of "biochemistry" as opposed to natural selection?
Bacteria don’t ‘develop’ resistance, it is, and always was, present in the general bacterial population, and the continued use of antibiotics selectively breeds that particular strain to the exclusion of others. Ending all antibiotic use for a continued period would result in a return of normal demographics to the bacterial populations.