That's why atleast we select the casino which have huge user base and been successful already for running their business with several promotions running around since we can assure that we somehow in the safe place knowing that they are already earning huge from their users and we can expect that they will last long and will not scam their users. Although license is not really a basis to trust but atleast we see them up complying to became a legal platform.
I agree with your second part that license is not the main element for trust but I am not agree with your first point. Because all the site was/should be new born and day by day they have to build up their reputation as well as as user. And as a new site they might have not a lot of users and they will have no trust but they will build fast or slowly base on their promotional offer, marketing, sponsor and so on.