What you’re ignoring for the sake of your argument is that the army would be on its own turf instead of going somewhere where they don’t know the land and there’s a big difference between Americans with guns and foreign militias backed by other countries. Also, don’t look up the death rate of Afghans vs foreigners in the 2000s war because it doesn’t look good for the Afghans.
Don’t know why you would bring up Vietnam, drones weren’t a thing back then, today the military wouldn’t even have to get off base to fuck up the opposing side.