Pestilence evolves to survive, becomes more virulant but less deadly. Killing host organisms is not a good survival methodology.
Overly used meds + poor theraputics = breakthrough strains. This is true whether the rona or flu, strep or staff
https://www.globalsecurity.org/military/agency/army/107sg.htm
Silk stocking brigade!
Whacked when Bubba became POTUS.