One has to view the LBII operation in the overall context of what the objectives were. The overriding objective was to force the NV back to the negotiating table. LB2 did that by inflcting a level of damage on those military and logistics targets that crippled the NV ability to continue the fight.
It was clear from the bombing campaign that we could and would range the country and destroy any objective that we determined necessary. The NV could not stop us from doing that, nor could they inflict sufficient attrition to make us stop. For the first time in the war, we unleashed the ability of the US forces to interdict and shut down their critical supply lines, and decimated their air defense forces, rail lines, port facilities (mining), and other critical facilities.
So we achieved the political objective by demonstrating conclusively that we could win militarily.
Our returned POW's reported that their guards and their officers showed real fear and respect for the first time as the LBII operations hammered the north.
Having said that, it was clearly a short-term goal that was determined by the US political leadership and, yes, it forced the NV to negotiate our departure from the fight, thereby clearing the way for their eventual betrayal of the peace terms and subsequent conquer of SV.
Linebacker II was a battle that we won, hands down.
The politicians betrayed our sacrifice and lost the war. That is separate from the operation itself.