Why are some people so obsessed with the delusion of uniformity?

Stereotypes
Fitting in
Astrology/Horoscopes
Gender "mentalities"
Bahavioral "statistics"
Opinion "statistics"
Which country or state or city "likes what"
The list goes on..

The real world has individuals with high variance, not mass produced copies catagorized into neat little groups.

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+1 y
I think people aren't understanding the question.

I'm not asking why people prefer belonging to groups vs being alone, I'm asking why they place people as similar to one another when they aren't.

And because I'm sure people will misunderstand that too:

A very small amount of people are just like you, the large amount that you stereotype aren't just like you, so why do you claim that they are? it's not going to result in anything, you can't fit in where you don't fit. So why stereotype?
Why are some people so obsessed with the delusion of uniformity?
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