Pageants can help you make a start, but I don't necessarily think pageant experience teaches you how to succeed in show business. It certainly doesn't guarantee it. But there is one big similarity. When you're a beauty queen, you are out and about, interacting with all kinds of people. Some of them like pageant people and some don't, but you have to try to make them all like you.
Show business is like that, too.
Even TV anchors have the same challenge. You have to make each viewer feel like a friend. Some women specialize, sticking to certain types of pageants. There are the Miss America girls, the Miss USA girls, the swimsuit girls, etc. Some women do all kinds of contests.