It will look the same if you do trading without skills such as only using feelings and relying on luck but if you do trading with good skills then it is very different from gambling, it's just that both are equally risky, risky to lose money but the risk in trading can be minimized by doing it with good skills and management.
Even if we do trading with skills and a little bit of luck, it will still be like gambling at the casino because there are also skill-based games on it. If you still believe that they are not the same, then you must say that trading is more winnable or less risky. The reason why people see trading as a very risky activity, is because they think it was very hard (which is true at first) because there are different things involved like doing an analysis, using complex tools, etc.. but once you learn them, you will say that it was only easy and you will now become profitable towards it.
Gambling on the casino other hand is easy to play because we will mostly just place a bet and push that run button but what makes it hard (to win) is it is mostly working randomly. Trading is not gambling, in a way that there are no flashy images here and sounds, so all must take trading seriously in order to earn.
This is our main goal here. Meanwhile, gambling in casino should be the opposite of it and yeah even for those games who are skill-based. They are only an added variation for some people who likes to think critically like for example when a person enjoys puzzles and mind games and most of the time, they can't also earn money here.