Most casino games are rigged and based on pure luck. You can only win long term in games where there is no casino edge and/or some type of skill involved. For example poker. But even then most people are not skilled enough and end up losing money.
I find trading crypto a much better way to make money than for example poker. But it can be both sketchy at times. Getting rich is not difficult at all, staying rich is. It's all about managing the risk. You have to think in probabilities and risk/reward ratio's.
Not directly but yes it can.
When those that place ads get good feedback in the sense that the ads attracts lot of people to their page, they will have more reason to place more ads and the news will spread on how effective it is to place ads on steemit.com. That could make steemit more popular and attract people.
I have a friend who does this but not as an only source of livelihood because I know he also have other online and offline jobs he does,what I know most people are into now is crypto trading,lots of people are in forex trading and also airdropping to help keep body and soul together.