I would never advocate quitting your job for trading, a job that will definitely pay you money at a certain time.
But in trading, you will sometimes succeed and sometimes you will face big losses, so such things should never be considered as a permanent source of income.
No matter how skilled you are, you will also face losses at times, there will always be risks and without the right strategy, losses are inevitable, so the safest way is to keep your job and continue trading side by side.
You are right, sometimes even professional traders face losses, even professional traders cannot make consistent profits. In fact, trading is very risky, which not everyone can be successful in trading. Now some newbies plan to trade with little knowledge and consider trading as a source of income, in fact trading can never be a permanent source of income. Again, some newbies plan to trade with loans, which is a wrong step, if they trade with loans and face losses, how will they repay the loans? As you said, I will say the same, the best thing is to trade alongside a job or any work, but you should use money that you can afford to lose.