Except that the throat culture takes 48 hours to come back, plus the time to get the patient started on the abx after that, on an infection that has a 5 day cou

Except that the throat culture takes 48 hours to come back, plus the time to get the patient started on the abx after that, on an infection that has a 5 day course to begin with, which got into your office somewhere on day 2. You wait 48+ hours on the backup culture, and you've missed your window to do anything with it. ...which is a big part of why it used to be common, and isn't now.