This is a great question. My take: our artists clearly—across eras—do NOT trust our ability to not fluck it all up. And it appears they got it right.
Notable exception, the
#LLAP timelines and universes. Very optimistically inclined and then had to fight for that optimism from DS9 forward.
QOTD: Why are so many depictions of the future so dystopian? Where are some positive depictions that outline how they got there and how they maintain it? And does everything have to so cold! Glass and steel. Is there nature in the future?