The most highly evolved of the dinosaurs
Part of birds' advantage was lack of specialization.
Then why didn't the troodontids survive?
Humans are teh only species that have ever become highly evolved
See above.
and avoided over-specialization, and Neanderthals did not manage it.
They were overspecialized and unable to think in new ways.
Another was small size, which was probably inversely related to intelligence.
It takes a certain amount of body size to support a big brain.
If dinosaurs had not suffered the great extinction tat that point, they would probably have given rise to a feathered version of us.