Gambling has been known to be addictive.
I'm generally a pretty risk-averse person, I've bought two lottery tickets in my life (once when I turned 18, once again when the Powerball hit a billion in 2015). Unsurprisingly, I didn't win both those times. I would much prefer to keep my cash in some kind of government-secured savings account, but the interest rates in those rarely keep up with inflation, at least not long term. The closest I have found to that is treasury-bills, and I do use those, but I still put the bulk of my money into ETFs, AKA gambling.
How so?
If you compare this to an FDIC-insured bank account, or a treasury note, there's effectively zero risk, so I would say it's decidedly not gambling, but the problem is that generally speaking zero-risk things don't pay enough interest to beat inflation, meaning that your money is degrading a bit.
Obviously there's a difference between YOLOing everything in GME vs putting a bit of money every month into VOO, but the latter still does carry some risk, particularly in the short-term.
Gambling is when the rate of return (over time) is negative.
Investing is when the rate of return (over time) is positive.
Suppose I buy a share in a company specifically because I believe in their business and products.
I think that’s pretty clearly investing, but are you claiming it would cease to have been an investment if the company went bust?
Over time, you're going to lose money gambling. (That says nothing at all about what the next roll of the dice will be.) This is why casinos prosper.
Of course, if the US gets into nukular combat toe-to-toe with the Russkies, your stocks will likely vaporize to zero. But you'll be vaporized as well, so it's a risk not worth worrying about.
Less extreme, if the US goes hard into socialism, the stock market is not going to prosper. But your other investments won't prosper, either, so again that risk is not worth worrying about.