This seems like an odd question to me. It's like asking, "Why buy a Ferrari when a Hyundai will do the job?" If you just want to get from A to B then yeah, sure, get a Hyundai, which in this analogy is equivalent to sticking to the bottom deal. Maybe there are other considerations though.
A Ferrari (like learning the centre deal) brings prestige with it, it's evidence of a certain kind of status, it draws admiration and attention from your peers, it has a certain kind of beauty to it, driving it gives you a unique kind of experience and, in certain specific situations, it performs in a way that a Hyundai couldn't. If any of those things are important to you then learning a centre deal might be important to you. If you are simply wanting to go to the shops and back, though, then save your money and get the Hyundai. By which I mean save your time and effort and don't bother learning the centre deal.
One other thought, though. People who really know about cars (Formula 1 drivers, racing engineers, etc.) don't buy Hyundais. In the same way, people who really know about cards (Dai Vernon, Ed Marlo, Steve Freeman, Bill Kalush, Ricky Jay, Jason England, Martin Nash, etc.) learn the centre deal. To me, that would be enough of an argument for learning it. Copying the habits of successful people, even when you don't quite understand them, is a great route to success.