If they leak the photos after they get the money, they might have less chance of getting the money next time.

They probably don't care for the photos. They care about making money and want to keep making money in the future.

They might not want to keep making money in the future. Sometimes, they score something big and leave the business.

Maybe you're right, but it still feels to me that leaking the pictures will not benefit the scammers much. They might have connections to other people that are still in the business and they'd harm them indirectly by leaking after getting paid. Why make more enemies? Also, why put more attention onto themselves after they already succeeded? Some people have very strange reasons they do things, but I still don't think it's likely. I think these things are organized with the top priority of minimizing the risk of getting caught.

You're assuming they're rational in this regard, but not rational enough to change their identity or select a different class of target in the future.

Even if they change both the identity and the target, it's less likely they are going to succeed next time if the photos were leaked. People can read about the story in the news and it can affect the perception of this entire type of extortion in general.