They have killed many terrorists over the course of years (Al-Qaeda Network and its affiliates),
But so many are still alive and doing well in "Jihad" IN Afghanistan, Pakistan and Iran. Safe havens are still present in Pakistan and Iran, training, nurturing, treating Taliban soldiers. So where is the value in all the "terrorists" that have been killed so far? Also US introduced ISIS into Afghanistan within the past few years, so while you kill 1 type of terrrorist(AQ), you nurture another one(ISIS). You're playing too many games. US probably brought ISIS in as an equivalent-but-opposite pseudo-Salafist militant group in Afghanistan. The countries that were afraid of this ISIS in Afghanistan were all US enemies- Taliban, Russia, Iran.
and have also prevented Taliban from imposing their will on entire Afghanistan.
But Taliban have imposed their will(physically) on 60% of Afghanistan and everyone but you understands that Kabul's hold on Afghanistan is rickety and weak. You're proud you've blocked the Taliban from controlling Afghanistan but by this time you should have already setup a functioning govt for all Afghans, but you've failed at that and this Afghan govt will start to fall or disintegrate the moment NATO and US troops pull out fully if they do that soon.
Perhaps you will not understand but many Afghans also desire democracy so it is not wise for one ethnic group to impose its will on others.
There's no consensus to support this! can you show me some stats that shows Afghans "WANT" democracy? Or isnt this just your western-leaning "democratic values" confirmation bias kicking in? You're just projecting your political views onto Afghans! its ridiculous! Afghanistan IS NOT America or UK. Boy you're wild. selling wrong thing to the wrong people.
It would be much better if Taliban and existing Afghan government reach an understanding and strive for lasting peace and good terms with neighboring countries including (and most importantly) Pakistan.
Yes, this is what we wish for. We all wish Afghanistan a peaceful existence and good development. But how we get that and if its actually possible, no one can be sure of.
About broken infrastructure in US, you must be joking. While US does not look new and shiny like China, it is still far better developed than majority of countries in the world.
C'mon bro. If you're American, you know US has MANY bridges that need repair AND train systems are old. Even Trump sold this "invest in infrastructure" to voters who voted him in, but offcourse he hasnt pushed it through, prolly cuz there isnt money for it(at least not yet).