Gambling is profitable to people who always have luck in it. Gambling is always risky in any aspect even with the small amount and with the huge amount. Many people will think with little investment we will make more money through gambling but it is always wrong. Gambling is always very risky and winning chances are very less.
Not just with luck. There are gambling games that doesn't need pure luck.
Im in my case have a great stats by doing sports betting so basically gambling is profitable to me. I don't believe that winning chances here is less like you are saying. It can only applied on house edge gambling games but not on a strategical based games.
Sportsbetting is sometimes profitable because some people claim that they know some knowledge regarding the game that is why they are going to win the game. When they are know what will happen then they will bet for it but everything depends on luck as well so sometimes prediction might be wrong and people could lose so it is not that profitable either