There's an old saying: lotteries are a tax on people who can't do maths and don't realise the probability of winning is miniscule.
I think investing is the easiest way to become wealthy. You need a bit of discipline to save up some initial capital, and then you need to do some brainwork and research.
Entrepreneurship is hard. You need an idea; you need sales ability to sell your product or service; you need administrative ability and you have to be able to manage staff. If you can pull it off though, it yields the biggest reward.
This is asking far too much of 80% of the population! :)