Publicly I agree with you especially if your identity is exposed since you will never know who can see your post and will have interest on your money.
But sharing it anonymously like in the forum is fine with me as long as there’s no personal information attached on it. As a gambler, sharing my achievement after an adrenaline fun filled game is satisfying when it resulted to a great win. It’s more on self satisfying act to make your day complete.
Nice. It's okay to share, who knows, maybe it will boost the confidence of another gambler that he makes a goal the same as you.
IMO, it's not always a negative thing. There are people who like reading positive vibes and winning a big multiplier is not like being boastful about it but telling other people that it can happen. I mean, it's not impossible which other gamblers think.
Also, it gives a chance to the one who will share it to inform others that they can do it too. Why? Because he is a legitimate player and not a streamer who might have a rigged system while he is recording his playtime.
Many don't believe those anymore but when the information comes to the gambler itself, then it's easier to be believed by other players especially those who have not yet experienced those huge multipliers in their entire life of playing whatever the game it is.
Yes, I think it will satisfy both the gambler who shared and the one who will read it. It's a big proof that it can happen to anyone.