I've only blocked a few communities and my feed is not only negativity.
It can be at times when something big drops in the news, but my feed is still flooded with fun memes and interesting articles.
Sounds like, at least partially, it's confirmation bias.
It's the same with a lot of us millennial people.
I graduated into a job market still largely crushed by the dotcom bubble bursting, had my entire life and career path destroyed by the GFC, then another destroyed by covid.
Let me just spend a third of my monthly food allowance on food I can make better myself to please the downtown economy god, I guess lmfao.