Crucially, it's all regulated. You have to be 18 to enter a betting shop or a casino. A slot machine has to be inspected by the Gambling Commission and must clearly state the payout ratio. Every business and employee involved in gambling has to be licensed. There's a voluntary self-exclusion scheme, so problem gamblers can ban themselves from being able to place a bet.
Lootboxes are effectively a form of gambling - you pay x, but you get a prize worth anything from 0.01x to 1000x based on a random number generator. That RNG isn't audited. Customers don't know the odds. There's no age restriction or controls on advertising. Nobody involved in the business is licensed or subject to scrutiny by a suitable regulator. The operators have no social responsibility obligations.
I'm a gambler myself. I think that US gambling laws are a bit weird. I don't want to ban gambling, but it needs to be properly regulated, regardless of the form it takes. I don't want to see children being stealthily introduced to gambling by predatory game developers.