This isn't completely true even if we are to look at it in the long term, this may not be true still, there are traders on the Binance and ByBit platforms who trade with leverage and apply there stops where needed according to their strategy and the make good profits at the end of the day. having a money management and a risk management strategy will help a long way in getting you not to suffer loses for comparison, even investors do suffer losses be it with or without leverage, if they aren't managing their funds well then they are bound to suffer the losses at some point.

Personally i see it that for you to stay profitable in both trading and investment, with or without leverage, you need a very good money management and risk management strategies as that will have a whole lot to do with how much you are going to gain and loose at every point in time so you know when to exit and protect your funds so as not to get liquidated and when you see an opportunity to make profits you know how well to maximize the profits you can get form that opportunity.