A 1 kilometer long bridge has to "bend" about 78 millimeters to follow the shape of the earth (simplified). A one meter stick 0.0078 millimeters. Do you think you can see such a small difference?

One could ask why the level of the ocean is not going down after removing a glas of water. It went down, but the change it's too small to see.

You can remove a grain of sand from a beach. There is less sand now but would anybody notice?