Just wondering why we see no curvature of the horizon from left to right?

If you are standing on a beach, with 135 degree field of vision and two miles of straight line sight, you should be able to see about 15 feet of drop on each side, right?

This would be exacerbated the higher up you went and the further you could see, because the horizon from left to right would also increase.

Why would you need to break 60,000 feet in elevation to see the horizon curve? Every point on Earth has the same curvature in a sphere, it doesn't matter what direction you look.

For example, at my elevation, I can see the mountains about 100 miles away. Which means the horizon is more than 80 miles wide.

There should be a curvature on each side of more than 1000 feet. If I turned my head left or right, this curvature should continue.

And if I looked out with the mountain at the edge of my vision, it should be pointed at an angle, not straight up.

??