So what is the motive for the government or whoever to lie about the shape of the Earth?
Like what benefits does it give them?
I can't see any. It makes no sense to me.
No one is lying about the shape of the earth. The governments are lying about space exploration, and they use the flat earth model (fake earth images and such) because it's the most popular theory of earth's shape and is widely accepted by most. If they didn't, most would not believe NASA and other space agencies are sending things in space.
Why not just say it was flat?
They probably don't know it's flat. The public is convinced the earth is round. So, NASA and others present the earth as as a sphere.
Also, whoever is lying to us would have had to have started hundreds of years ago because even around the time Christopher Columbus was alive, it was commonly accepted that the Earth was round.
No. No one is intentionally lying about the earth's shape. There are and has always been two competing views of the earth's shape. The spherical earth proponents managed to gain influence in society and indoctrinate people for the last few hundreds of years. NASA is simply faking space exploration as a way for powerful and influential people to embezzle money and they use the earth model that most already accept.
(It's a false myth that he proved the Earth was round, everyone knew already)
Of course he didn't prove the earth was round. And no one is saying the spherical earth model didn't exist prior to him. That doesn't prove the earth is round.