I think gambling and trading both require skills, if you don't have skills you can't win in gambling irrespective of whether it's a casino game or sportsbets and you can't win in trading if you don't have the skills of trading, you need to understand fundamental of a coin and technical aspect of a coin to succeed as a trader.
You are right, both need knowledge in order to increase success rates. But the chance in gambling is we will lose our all funds if we lose, for example, in a game where we have to predict the price of BTC, and if predicted wrong, while other opponents will predict right then all of your funds are there's. But in crypto trading, if you are in a spot, then you never lose until you have control over your nerves. For example, those traders who bought at $60K in the last bull run and then waited this long to book or recover the losses or profits, they would lose the funds if they failed to overcome their nerves and sell at low. Selling timely is also an art in trading, we don't have too many options to choose from in gambling, it's either in or all out but in trading there is still a chance.
That's why I won't say trading is gambling, as they are both two different things and we should know the difference, I don't gamble, but I do have a slight idea about how things works, then there comes those gambling platforms like that spinning bowl where a ball will stop like on some number and the owner of that number will win, that type of games require no knowledge as they totally based on luck, and thus that's the pure form of gambling I would say we should keep ourself away from gambling and relevant stuff.