~snip~
You are right, however, gambling still involves luck, including as you said in skill-based gambling also requires luck, it's just that the skills we have can increase our chances of winning when gambling, besides that, don't be too confident with the skills we have because there is no clear certainty about winning.
But in my opinion, there are also people who trade by relying only on luck, hoping that the transactions they make can generate profits while they have no skills or knowledge at all about trading, or their minimal knowledge so they only rely on luck, this is ridiculous.
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.