Gambling is not as simple as you think it is. You may think that it should be played just for fun but the reality here is, it's not. There are lots of professional gamblers whos doing gambling for a living.
The professionals are playing games where they can make a statistical advantage for themselves. Most crypto games do not fit into this category. However, I want to make a defense for crypto gambling. What they do offer is entertainment to the overwhelming majority of gamblers who are just out there enjoying themselves. And with super thin house margins, provably fair games and easy deposit withdrawels, crypto gambling has its advantages to more dodgy brick and mortar options.