A good illustration. Your phrasing "The bacteria has developed resistance to the antibiotic" is of course better understood as "the descendant bacterial cells h

A good illustration. Your phrasing "The bacteria has developed resistance to the antibiotic" is of course better understood as "the descendant bacterial cells have been ruthlessly selected for resistance to this antibiotic." But that is not an invariant characteristic of bacteria. It is perfectly possible to completely wipe out a population of bacteria in a particular place so that the bacteria have NO descendants.