Yes people can get rich in trading but not in an instant. And it also depends on how much you’ve invested and for how long too. I know someone who’ve invested his last pay at work and every time bitcoin reaches a new ATH he would announce how much he profited. But I don’t think he ever withdrew his profits and kept hodling up until now.
We know it is possible that is not the problem, the problem is that people expect this to happen to them and yet make no effort to reach that goal and think they can achieve those results by just investing a few dollars in a few weeks, their issue is their expectations, becoming rich is still possible even now as long as your capital is substantial, you know the ins and outs of how to trade and you are willing to wait for years or even a whole decade to see those results, but very few people think like that which is why they end up making a lot of mistakes which reduce their wealth instead of increasing it.