Rich from gambling can be only gambling site owners. They can be really rich - a lot of Bitcoins.
You might be right. But OP asking us, by playing gambling, not providing the service of gambling house. If the gambling house owners also a gambler, then he might be a richest person in my guessing.
Most cases gambling site owners would be more richer since we do really know that having a gambling site is really a profitable business since we do know that gambling houses do always win in the end which means they can make money as long there are players which play on their site.Mostly people on playing gambling gotten broke rather than on getting rich.