Every period of history is dramatic; sometimes I rewatch old episodes of a UK satirical news quiz, Have I Got News For You, and even in the best of years there was plenty of drama.
Is this an effect of social media and the 24 news cycle that has negative headlines on repeat?
I would say that the 1950s were better economically, at least in the US. If you were working class, you could make a living, and offer your children a better life than you had. That led to optimism.
But if you look at health, there were still a bunch of diseases that hadn't been conquered. Today is much better... if you can afford health insurance.
Technology? Today. No question.
Culture? They weren't on the 24th Marvel movie in the 1950s. Sure, there was a lot of schlock, too, but the original stuff was still original, not retreads of the same old stuff.
I like life now. But I'm not working class...
While there was a lot of innovation, we can say "original stuff was still original" even today. How would you classify Sorry to Bother You, Beau Is Afraid, or Hundreds of Beavers?
Plot wise, cinema back then still had a lot of stuff lifted from decades previous.
Like, Westerns date to at least 1903: https://en.wikipedia.org/wiki/The_Great_Train_Robbery_(1903_...
And the first Western film was inspired by Wild West shows that started before the Old West era even finished: https://en.wikipedia.org/wiki/Wild_West_shows
24 hour news cycle may do something, but we had daily bad headlines for a long time before that.
If anything new is making us depressed, it's likely algorithmic attempts on our attention. A/B testing on the most engaging content, leading to addiction, as in people who hate that they waste all their time on their devices and yet can't bring themselves to stop. At least some of that may lead to negative affect, including pessimism but also dysmorphia and rage etc. depending on what the A/B testing finds works best for your demographic.