people take it for months, yes resistant bacteria happens, but following rules is pretty simple.

Drug resistant bacteria develop when you stop taking antibiotics too soon. Antibiotics (typically) have a logarithmic effect, so that the last bacteria to die are the ones that are the “strongest.” If you stop too soon these are the bacteria that survive and reproduce - the ones that do not respond to antibiotics.

You shouldn’t just take antibiotics willy nilly because 9 times out of ten they do nothing, taking them just gives you something to do to pass the time while your viral infection clears. People are generally shit at judging if they have bacterial vs viral infections.

The other posters are right that feedlot use of antibiotics is a problem, but drug resistant bacteria happen for other reasons too.