Now considering that fact, I didn't see that many tutorials neither, I mean I know all the games myself and that is why I didn't need any but never put myself in the shoes of people who would basically go in completely blind as well. Maybe you should consider like a "tutorial" button or maybe "learn how to" type of button, it could be very very tiny somewhere on the page of that game and it would basically show on the website with clicks and buttons on what does exactly what and that would help these people out.
On the other hand I am not entirely sure if people who are willing to gamble all that much money to casinos have zero idea about gambling, sure there could be some but I doubt there are many of them, probably just a very few.
Most gamblers know very well how to play certain games and don't really need any tutorials. How often does someone go to a physical casino, take out a $100 bill and go to a Blackjack table and just guess how to play the game? Almost never. They probably won't even want to risk betting $1 if they didn't know what they were doing. Hence this is the reason why many of the traffic to casinos usually just plays slots since its pretty much automatic as soon as you pull the lever. Either money comes out meaning you've won or nothing happens which means you lost.
I think if tutorials or animations on how to play were required then most websites would have them. Even a simple link to some private Youtube videos would help. However its not really an issue so most sites don't post animated tutorials like that. The only sites in my opinion that need tutorials are those weird crypto games where you have no idea how they work since its a new and up and coming crypto gambling site and you can't figure it out even on demo that you just close the window and move on to the next site. I remember there was a site like this and all I remember is that it had 2 dice and had no idea how to play it exactly and after 30 seconds just left and haven't returned.