I lost money most in fiat casinos because I have known them since many years ago unlike crypto casinos that I know about 5 years ago. As long as you register on a casino and you started gambling, you are most likely to lose because all the games are most in favour of the casinos and not gamblers. In fact, most games in crypto casinos are in fiat casinos except just few. They are just the same if comparing which one is riskier.
I think the risks are the it's just a matter of which is more valuable to you, a loss is a loss whether you lose fiat or crypto...but I feel more comfortable with losing fiat currencies no because I'm happy with throwing my money away but compared to losing something valuable like bitcoin is absolutely difficult to deal with because as someone into cryptocurrency you know the potential of that coin you lost