The reason the buildings looked like they were collapsing is because the buildings were collapsing. That’s what buildings look like when they collapse. There’s nothing “systematic” about it as far any other contributing forces. The collapses of both buildings clearly start from the point of impact from the planes, from them burning at thousands of degrees for a period of time, and from no other point in either of the buildings. Indeed, the building that had been burning the longest actually started collapsing second because the point of impact was higher, so there was considerably less weight above the point of impact.
So the buildings were collapsing ... so why did the floors above the impacts turn to dust in mid fall? The video is very clear that they did.
I agree with your thoughts.
What made Building 7 collapse?