Its good for Science Fiction can be aspirational sometimes though.
Classic Star Trek has humans living in an idealistic society meeting some weirdo aliens doing some weirdo alien shit that causes a lot of problems. Then you realize we're more like the aliens than the we are like the idealistic future human society. Our society is alien to to an ideal society.
Then the Enterprise warps off to some other place to do some cool shit somewhere else and the aliens are stuck on their shitty planet because they're a bunch of losers what can't get past their weirdo shit.
The implication is that we could be the cool dudes in a starship constantly doing awesome shit. But instead we're the losers stuck on a planet that the people in the starships laugh at.
So the reason why an ideal future isn't possible is because we can't get past our weirdo loser ideas.
I can now picture Kirk, Spock and Bones having a chuckle about some weirdo aliens that can't advance because they're stuck in the rut of doomerism.
"It's quite illogical that they can't understand they can never achieve anything if they presume failure before they even try."
"Humanity once thought that way a long time ago but we eventually got past it. Anyway, off we go somewhere else to see some other loser aliens doing stupid shit we used to do!"