It's obviously true that convergent evolution, that produces similar traits across distantly related species, occurs. So your assertion makes no sense to me.
Flight evolves all over the planet, across diverse environments.
But in any case, there will be some commonality in environments across many planets, owing to what environments are the most probable hosts of life, and to the fact that the laws of physics are universal.
That works for flight, but not for intelligence. We can define what “flight” means, but we can’t do that for “intelligence”. Unless by “intelligent” you really mean “appears to be behaving like a human”.
Intelligence is a higher order trait so harder to describe, but it is still a discernible trait. Roughly speaking, intelligence is the ability to achieve an objective through modeling scenarios in order to determine more optimal behavior.
Intelligence across species shares common characteristics even between dolphins, apes and birds which all evolved it independently.