You've said something true about futures trading, but really one can never escape being greedy in trading. They may learn from their own experience, have emotional control and wise use of laverge, but things will not be as easy as we imagine and the practice will be very different.
I had to avoid futures trading because it's so hard to control my urges and emotions not to get greedy, so in the end I tended towards spot trading instead of futures trading so far. I can learn it, but I'd rather avoid something I don't understand properly.
Greed is a natural trait that humans have and the level of greed also differs from person to person. It is very difficult to regulate psychology if we are not used to it, greed will arise when we are faced with a choice that is a win-win.
I also even stay away from futures trading because the risks are indeed higher, but some people who are able to control futures trading, can take advantage of every movement to make a profit. Futures trading is not for beginners because the risks are greater and also psychological control will determine profits.
Those traders who found themselves in a better position in trading will succeed whether it was futures trading or spot trading. Greediness can be found in everybody but I don't think that was really the problem in futures trading because what I see is that it is our decision-making. And if we talk about strategies, I think most of us are using the same but what it went wrong is how it was been implemented.
Whether it was futures trading or not, many traders will often lose rather than make a profit.