My two satoshis:
Gambling is based on chance, while cryptocurrency is based on mathematics/calculations and cryptography.
You are not comparing gambling with cryptocurrency, but gambling with crypto trading. Crypto trading has nothing to do with mathematics/calculations and cryptography, at least at the mid-user level, and a lot to do with pure luck.
With gambling, you are betting against the casino house and board members, but with cryptocurrency you are betting against other people that have more or the same and similar amounts of money as you do.
Crypto tranding and betting are zero-sum games. Although you are right that you are betting against the casino in some sense, in reality for you to win there must be people who lose. You are not winning the casino's money, but the money other gamblers lose.
In casino gambling there is usually a guaranteed win for them because they have an edge on their games while in crypto it requires strategies and skill to top up your game.
Strategies and skill are overvalued not only in crypto trading, but in trading in general. University tuition fees, expensive courses, broker premiums from Wall Street's biggest firms, all this is nothing more than an illusion since since it has been shown that a monkey with a crossbow would obtain similar results.