They could be the same but the rate at which people lose from gambling is much more to be compared with exchange irrespective that they have similar features and of course they can't operate same way because gambling site is to have pleasure and ease ones stresses, at same time using money for it, although there are some games you may decide to play without staking a specific amount from the site.
All these makes it different from exchange because in exchange you can't have fun without you trading with money or you can entertain yourself with games rather it's trading so, apparently gambling site pays taxes same as exchange does because most of the exchange that are operating under some jurisdiction are paying taxes. For example, the US, there's no company that operates under the law of US that does remits their taxes including their gamblers if I am not mistakenly.
While I was writing this thread, that thought came to my mind, on the importance of fun and entertainment that make gambling significantly different from trading and to that we have to look at other points of direction which may be the reason why gambling sites does not charge fees, may be because their are more of fun and free, while exchanges must be paid for because there is no fun in trading and cryptocurrency threading is all about the profits which means it business oriented while cryptocurrency casino are entertainment oriented.
You are correct specially with the last part of your comment, cryptocurrency trading is business, and crypto exchanges are business oriented when it comes to trading crypto.
Meanwhile on that other hand, gambling is entertainment, even casinos advertise it that gamblers treat gambling as an entertainment rather than a means to make money.
But when it comes to what's fun to do and whats not fun, I can categorically tell you that on individually levels, trading and gambling are fun for whoever find any of both, or even both; to be fun, like me personally, I enjoy trading as much as I do enjoy gambling, in fact, if I must be sincere with you, I will tell you that I find more fun in trading than I do with gambling, I could sit for hours watching my computer screen while trading, analyzing markets, speculating, playing with charts and so on, but if I spend the same amount of time on gambling, depending on what type of game I am playing, I can easily get bored, specially when there aren't really any winning coming around to serve as a motivation to keep playing the game.