At the end of the day everyone only has 24 hours every day.
Each person needs to find what they're good at and do that. Maybe even do something that you're slightly good but pays way better.
Also automation can help people earn a lot of money passively. It all depends on many factors, but only working one job is probably not the best way to get rich.
But gambling isn't an automation job since you're need to play it yourself, if you referring to slots as your side job then it wouldn't work since house edge will make players loss. I don't believe "One Man Show" is making them rich, it just make their life way better. As you said above we only have 24 hours every day and it's impossible for a person to get rich alone.
It's better if he's looking for another side job that is more promising rather than become a professional gambler.