But, people who are rich would be bothered, there would be people trying to login, try to hack, try to bother them with pm's and phishing links and many other things. That's why it's not a smart idea to share who you are when you are a rich person. I hope to god that I would have that type of problem one day

. I rather be rich and scared then poor and relax

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This is why the Rollbit 2FA features also allows you to hide your username and many big whales have done so like the Rollbit boss who has wagered over $1 billion has used this feature and is unknown.This is good move to prevent hackers trying to look into their account and as you said but sometimes they also want fame to share wins with others so it all depends on our way of gambling and handling situations.
This is not just about the rich people, this should be done by every gamblers, they need to protect their identity and it's good to have option to remain anonymous and hide your username, also if there's a feature about the difference of username and display name much better because some site have this kind of feature. Rich people will always follow the security, they are more willing to provide their personal identity or fill out the KYC form just to be sure that they are safe and secured on that site, there's also an additional security for them because the site can't afford to lose them.