Maybe this has already been discussed, but Trump made a claim that Taliban snipers were killing American troops in Afghanistan until he negotiated with them. He claimed that after his negotiations not one person died for 18 months because he threatened to bomb "Abdul's" house (not the correct name).
Let's suppose this story is somewhat accurate. What was stopping him from doing something about this between Jan 2017 and Feb 2020? It took him 3 years to get around to this? Was he too busy coming up with his Health Care Plan concept? And it's not like Biden got into office and the Taliban started attacking again because he was weak, they got one suicide attack off as the military was leaving the country and that was it.
All Trump did was acquiesce to the Talinban's demands of prisoner releases, and they were happy to comply. It wasn't some great plan, it was him rolling over because he didn't have any personal financial interest in Afghanistan to defend.