I would have thought there are already poker rooms on a blockchain, although it could be a fee issue as every bet would be a transaction I guess? If you use centralized platforms I'd be damn careful not to get robbed if it's a new platform. Playing on Pokerstars is just fine. You don't have the same anonymity/privacy, but I have never made bad experiences with them.
If every bet is a blockchain record, it will make the game very expensive even for the winner. Because everyone will pay transaction fees that aren't normally cheap.