These three ended up being so great that they are covering like half of all the bets probably when you look at how much they are wagered total, rest all combined probably covers the other half, which is a proof that these three alone leads the crypto gambling world.
Honestly, I'm not sure if they really are the real leaders in the crypto gambling world, there are no statistics that I read that would prove it. Maybe popular in the forum, but in another platform, not sure if they are, correct me if I'm wrong though, but I agree that these sites are reputable and have a lot of loyal supporters/gambler in the forum.
Then you need to check how big Stake and Sportsbet are! They are sponsoring English Premiers clubs! I guess most of their players are not from the forum! Check news about Drake and his wagering on Stake, it's something crazy for most of us! Aside from all other things, Stake and Sportsbet offers the most in crypto sports betting, and in some other stuff, only they offer some other markets! For example, betting on Eurovision! You can't find that on all crypto betting sites!
Freebitcoin is something different! I wouldn't call them a casino, Freebitcoin is definitely something special, they have some games, but they offer other stuff as well! They last for years, and we can bet they are here to stay!