Certainly putting an NFL Stadium in Buffalo was not going to be easy. Parking, transportation flow, the current poor location of the highway system right on the water front, the Skyway question, and the environmental impacts and clean up all made it harder than just throwing up another facility in OP. This had to be viewed as a bigger project than just a place for the Bills to play.
It would have been an ambitious project that had to go beyond football to make it feasible. As you stated, the important thing is we got there. The Bills are staying, at least for a while longer. I would not call the final decision a rousing success but it is a compromise decision that took the easiest and least expensive path. The Peace Bridge analogy is a good one. Remember the silly excitement of putting a Bass Pro Shop into the old Aud? Another example of Buffalo thinking small and getting paralyzed.
I saw the downtown stadium as an opportunity to get rid of the old and ugly and re-purpose it with modern and beautiful. The Stadium, green space parks, parking, hotels, restaurants/shops, access to the waterfront -- maybe by the end of the century?