Is there any casino that's very popular in crypto yet no license?
I have no idea but I doubt a crypto casino would become very popular if it does not have a license in the first place. A license may not be a guarantee that a casino would play it fair, but at the very least a license could somehow assure players that the casino has a certain amount of accountability for their business, that the casino is legally operating.
Also, if an unlicensed crypto casino becomes popular for its services, I guess they would also consider getting a license for its growing gambling business.