Both can generate profits very quickly. But don’t get the wrong idea, the main purpose of gambling shouldn’t be to make a profit, whether large or small, but purely for the sake of having fun, in this case, if you end up in the black at the end of a gambling session, that’s just a bonus.
Meanwhile, in trading, making a profit is common because that is the primary goal, and it’s also easier to identify the risks and potential profits involved. As for how quickly you can make a profit, that depends on your capital, strategy, and money management skills.
I don't want to belittle gambling and people that are good at it but you might have plenty of people that will profit from trading than people that are into gambling. If you teach 100 people how to trade and they mastered everything and you set up an account for them to trade, if they don't trade like gamblers and do everything according to how you train them, you will have at least 70 people that will be profitable but I don't think the same will work for number of gamblers.
Trading has a rule and pattern for people to follow, gambling does not. Anybody you see making money from gambling is doing it because they are making money from it. There is no concise rules and way to make money. There is better opportunity when you trade than when you gamble but I know many people will choose gambling because they don't have to sit on their screen for long time.
If I had to pick one, I'd still tell people to go with trading. But trading is not as simple as you make it sound. Its not like regular job where knowledge, hard work, effort will eventually pay off for sure. If it were that simple, we wouldnt have so many people losing money in market, because quite a few traders are actually serious about it.
At the end of the day trading is still probabilistic. Even if you have all right thing in place, you can still lose if luck doesnt go your way. You can do everything right and still take a loss. That's just the nature of trading.