You’re not going to kill every last member of the Taliban. They are part of the social fabric of the country. That would require a genocide of a good percentage of the Pashtun population.
“US Principal Deputy Assistant Secretary for South and Central Asian Affairs Alice Wells has said that she has been told by her friends in the Afghan government that the Taliban are part of the social fabric of Afghanistan, and believe in the nationhood of country.”
Taliban are a part of the social fabric of Afghanistan, Kabul tells US diplomat – The Express Tribune
Alice Wells says ultimate solution to Afghan conflict lies in a political resolution, not on military battlefield
https://tribune.com.pk/story/1638116/3-taliban-part-social-fabric-afghanistanus-diplomat-told-kabul/