You have one, massive incumbent who innovated a lot of what we see today (Stake); multiple competitors who hold a small but notionally considerable percentage of the market (Duelbits, Gamdom, Roobet, etc); a rapidly evolving space with huge potential upside. The only thing that’s missing is the competitor that will finally give Stake a run for its money.
Stake.com is not the only one that's been doing what its been doing and I don't agree that there is an absence of competition in the Cryptocurrency market, it is just that Stake has long years of existence and they have established loyal supporters since they started back 1998, others are just building their reputation and community, their closest rival Duelbits just started 2020 but they have achieved a lot, it will be different five years from now, Stake.com is just reaping what they've planted on over 20 years of their existence, you cannot expect to beat Stake by other casinos that are 2 to 4 years in its existence.