In other words, it makes the copper allow much stronger than mild steels, like the stainless steels, and on par with strong (but by far not the strongest) steel

In other words, it makes the copper allow much stronger than mild steels, like the stainless steels, and on par with strong (but by far not the strongest) steel alloys. Imagine cutting stainless steel with a copper-based blade, and not the other way around.