2. Bigger paychecks.
Not all rich people are gamblers but they certainly have more chances to gamble if they wanted to. According to data, the higher the income is in some countries the more people gamble in that country. Since the average citizen is earning a lot, even if they spend quite a significant amount of money in gambling this will still not cause financial doom.
This is what I think. More people gamble for the sake of money, not for entertainment and fun. Sometimes we wonder why poor people gamble and spend more money on this stuff despite their situation, because they believe that winning in gambling is a great opportunity for them to change their lives. It means that bigger rewards attract players. That is why we see casinos take their challenge to set bigger jackpot prizes because they know how it influences the mindset of people to gamble.