When it comes to compulsive gambling, the monetary risk is an integral part. People who suffer from it get their fix not by winning but by putting things on the line. This is why gambling is almost universally regulated, and yahtzee is not. It's mind poison for some people.

Saying that "time" is a currency sounds good on paper, but in this case it doesn't work. Those whales that spend tens of thousands of dollars on loot boxes would not have spent an equal amount of time otherwise.

It's predatory, and it's bad.