Kind of neat, especially with a bit of skepticism toward the bigger is always better claim. Lot of "really" large animals, not actually that successful.

Elephants, Rhinos, Tigers, not especially successful. Start to become really high value targets with limited ability to defend against threats from every direction, and almost every nearby animal is "red circle", including humans. The Asian elephant is Endangered, the African savanna elephant is Endangered, while the African forest elephant is Critically Endangered. The the black, Javan, and Sumatran rhinos are Critically Endangered. Tigers are Endangered at 5% of historic range.

Dinosaur replenishment rates became negative in the Late Cretaceous, even before the Cretaceous–Paleogene extinction event. More species were going extinct than new ones were evolving with a decrease in the development of new traits or adaptive strategies. It all started stagnating, and then they could not cope with sharp changes.

A lot of cities are similar. Paralysis, stagnation, difficulty dealing with threats and changes, and almost every member of human society views them as a high value target. Why target podunk nowhere for pocket change, when a single success swindling New York or Los Angeles is millions. Politics targets them constantly. Now they're even drawing federal military responses.

Bigger's definitely got issues.