There are good arguments that gambling isn't exactly a zero-sum game. (Non-addictive enjoyment, hobby, relaxation, etc.)

But you're right in that the vast majority of players in gambling (including the house) are either (a) being fleeced, or (b) fleecing others. When the majority of users/members of a particular system are either victims (in some sense), or profiting off victims, I question the amorality of that system. So traditional morality called gambling "immoral" for good reason, I think -- if only because of this emergent, victimizational behavior it encourages.

It seems to me that economic regulation exists primarily to--and functions ideally when it successfully does--protect the vulnerable and prevent victimization. So it seems right and good to me that gambling is outlawed in most of the US.

Are you referring to the sudden boom of the general public dumping their money into cryptocurrency hoping to get rich?

Hell, I’ll bite here and assert the same as my parent comment: the folks who dumped their life savings into crypto made a personal choice. I fail to see how the rest of the market bears responsibility to those who lost their “investment”. So long as everyone is playing by the same rules, there’s no way you should be ethically responsible from benefiting from other’s losses.

You signed up for the risk when you chose to play. Do you believe that if I dump my money in a stock and it tanks, investors who benefit from that are now responsible for the money I’ve lost?

Gambling is not zero sum, there's the enjoyment (which is the most important factor for an addict, unfortunately), the percentage the bookie makes, the investment in facilities (shops, communications, race courses etc) that all occur because of an exchange of money.

Crypto is not a zero sum game, because money is being printed in the Forex markets all the time, which bleeds into the crypto markets. There is a lag time, called the Cantillon effect, between when money enters circulation, and the arrival of downstream purchasing power inflation.