Cashing out allows you to claim your winnings before an event is over, and some sites may even allow you to withdraw your bet if it looks like you won't win. As these sites are knowingly putting you in danger of the law, they can not be trusted.

It is also helpful to read the contribution rates for casino games. There is no guarantee that those sites will keep your data safe, they may not pay out if you win and they may try to scam you in the future.