You are right, trading is not a dangerous activity, but it is a risky activity. The main risk is losing money, but the reward is gaining profit from it. If traders really want to be successful and get rich from it, then they must be disciplined and not force their will on the market too much. We cannot dictate the market, meaning the market can change at any time even if we have to go against the trend.
Traders who are greedy and overconfident will basically find it difficult to develop, they may have to go home empty-handed. If they are disciplined, then they will probably succeed, but still with the right approach and strategy.
It is not only trading but most businesses that actually has the possibility of very high profit definitely has same if not higher possibility of actually losing. Trading carries same risk of losing and gaining the one thing that actually differentiate someone who is earning and someone who losing in trading as knowledge is the psychology of each traders. Once a trader has the substantial knowledge and the psychological skills then such person can turn trading to a successful one.
This doesn’t mean that with knowledge one cannot lose but the lose will be a calculated lose and most of the Time the successful trades aren’t even much higher than it but the profit covers far more than the loss plus the gain, so for someone with a good psychology to actually manage funds well trading is definitely for them.