Why are people on social media so mean?

Whenever I spend a lot of time on this site, my mental health plummets and fall into depression. Some of the comments or opinions I read here seem very cynical and shallow, whereas others are too pessimistic. Also, a lot of users have a holier than thou attitude/"I'm so smart and superior to everybody else and if you disagree with me you're an idiot". Of course there are some good people that try to help, but those are few.

Yes, this is rant, I had to get it off my chest.

I'm sure I'm gonna get comments along the lines of "don't let the door hit you hard on your way out".

Why are people on social media so mean?
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