That is because Poor people are mostly to be wanted to gamble for easy money
Everyone wants to earn easy money but in terms of this reason, gamblers are not choosing any status in life. But it's not really a hidden secret that the higher percentage from the poverty line is into gambling because that's what they think is the way to earn easily and get out of poverty.
It was too unfortunate that many poor people wish to have luck in gambling. And instead of keeping that money to feed their families, they gamble it and lose.
For me, slot and any form of gambling is not a problem and will not cause any harm, what makes this becomes a problem is the mindset of the people. They rely on luck to improve their lives instead of working hard. They really think that
easy money really exists in the real world.
These poor people bet instead of saving the money is due to the mindset that what more they can lose since they are already broke but if they win, it may be a life-changer for them. I don't favor that mindset but that's the reality.
Taken as an example, I play dice for a purpose of hitting the jackpot. I spend around $6 worth of BTC every session, that is 0.0003 or 30k satoshi BTC @ $20k per BTC back then. I bet with 100 sats just to qualify for the Jackpot, left it on auto bet while doing sig campaign posts. When I came back to check the dice page, I found out that I hit the jackpot worth 0.9xx BTC. For me, $6 won't get me poor but the jackpot of $18k+ can give me a decent life for years considering where I live.
It looks like a pretty detailed study but it wouldn't be the first time I've seen such a detailed study that gets it wrong. And I don't know if they are focusing on the right thing, because what is clear is that instant betting is what people are hooked on much more than it was 30 years ago. Nowadays you can bet on practically anything, at any time of the day from your mobile phone, that's what gets people hooked. Not like 30 years ago when you had to physically go to a place to bet.
The more reason slots will more likely to cause addiction, because, you can access it anytime, anywhere, without the restriction of scheduled gameplay unlike sports betting.
Music is addictive, watching porn is addictive and everything can be addictive in someway for someone sonwe can't simply generalize the things and target particular game. Personally when I okay slots I just keel on going but I have seen people eho drown in the sport betting as well so it really depends on what kind of game they love.
True that, we have our own preference, while you probably are drown to sports betting but I am more interested in a slots game, even I favor dice than sports betting probably because I hate scheduled game

, I play when I wanted to play and that's it.