Why flipping triangles, not normals

I feel asking this because I made the mistake thinking flipping my normals would show my mesh from the other side. Reversing the triangles seems to be the solution. But why so and why isn’t that documented in the Unity docs?

In realtime graphics, the normals are only used for shading but not for culling. Culling is determined by what’s called the winding order, namely whether the triangle vertices are clockwise or counter clock wise.