This is why it could be good to test them with little money first, that's if the bonus offered is so important to the person. If not, I would advise anyone to go for the old and reliable ones that one could review well online and have rest of mind with.
Another thing is the KYC, I simply can't deal with the casino which is no KYC, it automatically means they are not regulated.
I played with casinos that doesn't ask (from what I am aware of) for KYC before they were doing lots of promotions here and are managed by reputable managers, if they aren't, I won't play there. These casinos though, are now asking for KYCs for some of their users. They were also launched their casinos around that time. Personally , I would only trust new casinos if I think that they have good professionalism and engagement with the community, which is rare to see nowadays since lots of potentially scam casinos are being launched from time to time.
Better stay away from kyc sites. New online casinos are always looking for ways to improve the gaming experience and with the benefit of modern technology, they can enhance player entertainment and implement the latest trends. Recent trends may include gamification features and sites are using new platforms and using the latest technology so sites need to be reviewed to protect against scams.