Skill is the basis for success and with luck can make everything more perfect to ensure victory or some benefits, without skill someone will only continue to deposit money to be lost because luck also comes without realizing it, even no one can really guarantee someone to be lucky at all times.
In gambling or trading if only rely on luck, in the long run they may be able to spend all their savings and even sell various assets to be able to cover all losses, only fools do all that.
Of course luck will not happen often, because if it happens often it is no longer luck. It is certain that if they gamble or trade by relying only on luck it will make them lose their money, because it is impossible for them to be lucky every time. In gambling there is a possibility that skills can help us to get victory because with certain skills it does increase the chances of winning, but in the end it still involves luck too.
You are right, only a fool would persist with such a perception for a long period of time, because expecting luck to change everything is ridiculous.