Some falsefully speculates that they won just because they want to pave an ease to those who has been advising them to quit or limits gambling simply because the gambler has been unlucky to win instead he keep betting over and over without a good bankroll management in their gambling carriers.
They basically do this because they feels disturbed and inconveniences of the people's opinions and advices towards the gamblers unprofitable gambling experiences
Well I guess people fake their status in order to give sound advice to majority of the gamblers here as this is a discussion.
Though this may be the case, I do agree that there are people who fake their winnings in order to convince others to try what they are doing. In some cases, also, there are people who fake their winnings by indirectly promoting a certain gambling platform, in which the latter has rigged or questionable results and outcome.
Unfortunately, we cannot 100% detect if people are faking their said winnings by giving advice. The best thing to approach this kind of problem is to be rational and cautious- if what they are saying makes sense, then it is up to your good judgement whether to believe it or not.