why does everyone think the earth is round?

Not everyone does. Next question.

The ancient Egyptians noticed that on a certain day of the year you could see the sun from the bottom of a well at noon, but only at Syene. You could not see the sun from a well directly south of Syene. So they measured the angles and calculated the diameter of the Earth, and they were very close to the correct figure.

Not so well known is that philosophers in China noticed the same thing, but they assumed the earth was flat and calculated the altitude of the sun. Needless to say, that was not a useful bit of knowledge. Sailors know very well what shape the Earth is, and China has never been known for its great sailors.

Technically the earth is spherical, and the earth has been proven that the earth is actually spherical. Also the reason why we can't see the curvature is because it's gradual the earth is very big so it pretty much looks as a flat plane but it isnt

Most people believe what they are constantly told as it's a form of brainwashing the masses in order to control their minds. Don't worry, there are many others that are waking up to the truth, and becoming more aware of what's around them.

because there have been pics taken from space proving the earth is round

you're ignorant and so is everyone who believes the same as you. stop wasting people's time on meaningless stuff you know the answer to

Because of some historical exploration

Because we aren't ignorant like the guy in the video.

It is more eliptical than round

It's square, but who cares anyway.