It was not a winnable war. The secretary of defense, McNamara, admitted so, and still allowed thousands of young men to die.
It wasn’t a total war, either. I don’t think anyone would think Vietnam could have prevailed in a full-blown, total war with the US.
The US killed an estimated 1,000,000 NVA and VC, and suffered under 60,000 killed in action.
It was a brutal and pointless conflict, IMO, a stupid proxy war pushed by politicians. The soldiers didn’t want to be there. Also - the North Vietnamese are too often dismissed as measly rice farmers to magnify their “victory.” They were battle hardened, well equipped, versed in the terrain, and had just successfully repelled French colonial powers. They were fighting for their homeland, while US soldiers were unwillingly drafted and sent because LBJ wanted to flex dick on the Soviet Union.
It was a horrible, brutal and embarrassing proxy conflict that should never have been escalated by war hawk politicians.