Definitely trading , everything else is most of the time a scam and gambling make you greedy with time and you eventually lose everything If you don't want to stop. In the case of trading , If you lose there is no one to blame but your self unlike of gambling where you accuse the website of scam or cloudmining that keep closing it doors and run away with funds etc...
Agreed, on this things. Being greed is most of the time is the reason why majority of the gambler went to that position. But it is always starts at the behavior if the player in the gambling sites. But still the best source of bitcoin is always doing trade in the market place.
You are right, I think trading is one of the best thing when we talk about the best source of getting bitcoin nowadays. I say trading, because there is a high volatility of price in altcoin financial market. So you can learn how to do trading and when you have some great knowledge you can make a good money with it. It's not easy, but anyone can be a good trader by learn a lot and get some experience of lossing.