Copper works great if you have perfectly flat surfaces, both block and head. In fact, it is far superior to paper or fiber or other types of gaskets provided the surfaces are flat. Other (non-copper) gaskets work better where the surfaces are not flat as they are typically more accommodating of the bowed surface.
If you have a flat surface you will not get a burn through with a copper gasket.
As usual, the story is a bit more complicated, and the the topic at hand needs to be considered in the broader environment.