I wasn’t born yet, but wasn’t the real problem with the Tet Offensive that it made clear all the nonsense about progress in the war was just that - nonsense? It seems clear to me that for the Viet Cong to execute the attacks throughout the country meant they were far from beaten (though they sustained heavy casualties in the attack itself).
In the end the VC shot themselves in the foot with their brutality in the cities they briefly held with their mass executions of anyone working for the Saigon government; it ensured there would be strong resistance in the South to communism (and that resistance only died when US aid stopped and ARVN guns had few bullets left).
That was the deep state propaganda. The Military set the communists back by about 4 years. It was about 1972 when the commies started gaining enough people and equipment for a big fight again. There were about 17 commies killed for each American. TET backfired big time on the commies. The war was being won but riots at home and Crinkite convinced LBJ to pull out
The Tet Offensive had almost completely wiped out the Vietcong soldiers...