dead end candidate

1. A thing that prevents others from beating it by being too good, but cannot not evolve to get any better.

2. Whatever SFIA (famous youtuber) mean when he said that dinosaurs are a dead end candidate. (forgot which video he used the term)

Dinosaur hater: you always talk about wanting dinosaurs to survive the asteroid impact, but you forgot that they were a dead end candidate. Dinosaurs do not have precision control of their hands to make technology. And, dinosaurs eat the animals that do have precision control, such as early primates and other dinosaurs that had better hands.
Dinosaur lover: oh yeah, you always liked the soviet union, but they were also a dead end candidate, but for social progress. The soviet union oppressed freedoms by banning lgbt. The soviet union had many times the economical and military power compared to the USA. And, the soviet union cannot do social progress because all their citizens were blue-pilled and too busy enjoying their large purchasing power to notice the oppression.