I seem to remember Robert Bakker saying pretty much the same thing about 15-20 years ago.
That he did. If I recall correctly, his analysis of his diggings seemed to show that the hers and major other plant eaters were in decline. This, of course had effects on the carnivores who had grown to such monstrous sizes they had started eating each other to a greater degree than earlier species. I can’t find it but my memory is that a recent article on evidence of cannibalizing for T-Rex was again found.
Bakker is full of controversial ideas, most of which eventually prove true.
I also remember hearing him skeptical of the asteroid impact hypothesis for dinosaur extensions.
