That problem is fondant.
What is fondant? You have probably seen it before. It's a layer of rolled sugar, water, glycerin and gelatin that has been laid over the cake to make it look like a cannon ball. No doubt, fondant makes for a stunning visual for a cake, but this was something we were meant to eat, right? Here is a cake with fondant.
Doesn't even really look like a cake, does it? That's because it isn't. There is a cake in there somewhere, but it's protected by a layer of sugar armor. I think the cake above is really very nice looking. I would love to blow out the candles on this cake and then put it aside and eat another cake.
Where did this fondant stuff come from? I never encountered it when I went to a friend's birthday party as a kid. It was once resigned to wedding cakes and cakes for parties where everyone oogles the cake and leaves before it gets cut, but I have done very strict statistical research (not really) and determined that fondant has become more popular as people have been watching more food network shows about making incredible art cakes. Everyone has seen these amazing cakes, but you never see them eat them on the show. You might as well make them out of sculpey.
You can achieve some incredible results with fondant. Just check out this google search.
Amazing somewhat-edible creations.
The cake in the picture above came from a perfectly respectable baker, Miette. They make great cakes and have plenty of wonderful options without fondant. If you want a centerpiece, I recommend flowers, if you want a cake, I recommend frosting.