There are many to choose from, and each person has different ideas about what may be “worst”.

1984 is pretty bad. I’d read the book, though there are films, as the book really explains and expresses the situation.. Part of what makes it bad, is how close it is to nasty and insidious parts of actual world developments. It touches on several themes that deserve attention… one of them being that everyone has their own worst situation.

One of my favorite dystopian ideas is the nightmare that you die and go to heaven, and it’s full of atrocious Christian televangelist types.

The world following the Day Of The Triffids is pretty bleak. Society has fallen. Many are blind. Plants are attacking the people.

In fiction, “One” by David Karp describes a future where the state is methodically wiping out the last trace of individualism in an ordinary person who believes he is a conformist.

The one in Idiocracy, where everyone is an idiot, where everything is controlled by corporations, where the government is now openly sponsored by corporations, where the president is an loudmouthed, moronic, ex-entertainer.
It is the worst, because it is the most realistic.

The Platform is interesting but dark.
Generally the future looks more bleak than light, for me that’s sad but probably realistic. Will we get worse or better? The current trajectory is sad.