The US lost over a trillion dollars and now are negotiating with the "enemy" they fought and lost some of their best special operators against.
Your understanding of war (Haris Ali) is very similar to America's (bomb 'em to the Stone Age) --- the problem is that "leveling" doesn't work when an indigenous insurgency has popular support and enough caves to wait things out (sort of already living in the Stone Age!)
As others have pointed out, America no doubt has the military might to vaporize entire continents (let alone weak countries), but it can't due to a number of reasons --- especially these days. The Afg T know this very well --- and a bit of pressure through this tactic is a good idea to get things moving in the State Dept and to override CIA wishes of not reaching a peace deal.
USA can break the Taliban easily if they want to.
It is called drill-bit/finger nail strategy. I will let you figure out why
https://www.reuters.com/investigates/special-report/mideast-crisis-iraq-militias/