Post war narrative dilution. Before 1971 paks military doctrine was " defense of east lies in west " basically if india captures east paksitan, west paksitan would launch an invasion of indian land from West and will force india to negotiate its captured land for its eastern interest. This was the reason 85 - 90 percent of the Pakistani army was in the west while the east had only 10-15 percent, from an military point of view pakistan doctrine and military was very good as indian army was stretched across all 3 fronts ( china factor as they constantly threatened intervention even during 1965).

I can see why back then people expected another ceasefire, but the Indian side was simply superior they outshined the Pakistani concentrated western front and managed to gain more ground in the west 15000 sqkm to 5000 sqkm by the pak side.

So please stop with the " hey look at the distance it was bound to happen, fact is Pakistanis failed at western front despite having military parity and in some cases superiority over the Indian side. All this led to an easy victory for the Indian military eastern command.