Just because they can fake it doesn't mean they can make it with the methods they have that doesn't make it. You can be over confident or maybe just enough confident to look like you are a good trader, however that doesn't change the fact that if you are not making any profits, you are not a good trader. So, you can't fake trading, you can't fake profits in trading that is not possible, mathematics are mathematics and profits are profits. Either you are a good trader and have some profits or you are a bad one and have losses.
That is why you could give someone else your strategy to make money in the markets with very specific instructions about how to do it and they will never make any money because they will not know why you take a particular step since they were not the ones to device your strategy, so they will eventually deviate from it and then just when they need your strategy the most are going to make a mistake and lose an amount of capital that will make impossible for them to recover that money by trading.