How little do you know about eggs? The shape of an egg is designed to be strong to forces imparted on the egg from outside but weak to forces exerted from the inside. Newly hatched chicks have a special tooth called, big surprise, the egg tooth, that is specifically there for breaking through egg shells.
And yes, you could just smash it on the floor, but fat lot of fucking good that'll do if you want to get the egg out of the shell to cook it. The point is, you can't just rap it with your knuckle or give it a tap on the counter like a chicken egg. If you want to get the egg out of the shell, you either need to use a drill, or literally smack it with a knife to chip away at it. A mother ostrich sits on the egg, and they weigh more than 200 pounds, so you're better believe that's a strong fucking egg. The shells are 2-3mm thick, about 10 times thicker than a chicken egg.