For the arts, the possibilities have exploded. You can shoot an entire movie for budgets that are in the budget of individuals/small groups. You can find an audience for your art orders of magnitude bigger than anything you could find then.
Commercially, you can start high tech businesses in your garage that weren't even dreamt of in the 50s.
As for space, we're currently landing rockets on ships. We're actively planning Mars exploration.
The UN still promises global peace. The second half of the 50s had much worse nuclear saber rattling than anything we see right now. The Korean war very much was a high risk of US and USSR clashing directly.
I really think you romanticize the 50s. (I strongly encourage talking to people who lived through the 50s, especially minority groups)
Again, I really want to say "you're completely wrong" here - in terms of GDP growth, the 50s were great. In terms of sharing that growth (as opposed to concentrating wealth in a small group), they were great. BOth of these only apply to white men/families, though. And I deliberately exaggerate the picture in the other direction to show how much this is a question of framing.
And your right, one culture can be happier than another. We know which cultures are happy, and we have a fairly good idea why they are happier. It's on us to change our culture if we want that happiness.
You see this as a dark picture. I see it as a call to action, and the potential to make the world so much better. I don't know what the chances of success are, but I can promise you that seeing the future as malleable and culture as an ongoing project makes life better than focusing exclusively on the darkness.