That's true, success stories are shared much than the losing history. Whether we are into gambling or we try to follow any of the gambler, it is our responsibility to have prior plans as well as set our limits. The same luck of the one who has succeeded out of gambling won't be with us, so we are supposed to have our own strategies and tricks to increase the winning probabilities. Moreover the right exit strategy could get you small profit.
This is very common not only when it comes to gambling but in many other things, people have a tendency to try to hide their mistakes and losses and to show off their successes and their good decisions, I do not use social media that much but take a look at it, do you see many people admitting their mistakes and all the things they did wrong or their losses? Some do, but for the most part what you see is everyone sharing their good experiences and hiding everything else from view.
Yes I agree with you this is called the
survivorship bias/fallacy, and it's not always the fault of the successful speakers, because people usually tend to listen successful stories and not losing ones. So they often think they could win by simply reproducing a scheme used by a past winner, while the guy just got lucky actually. When you have 0.0001% chances to win at a gambling game, there are 99.9999% of losers but 0.0001% of happy winners ...
This happens very frequently, another example is the people that use the strategy of martingale, on the surface the strategy seems flawless because the only thing that you need to do is to keep doubling your bet until you recover your money back and it seems to give you very favourable odds to keep winning, and since there are probably millions of people using that strategy they are bound to be some people that have never gone bust with the strategy and they think that this is because of their skill when in fact they just got lucky.