I believe that if we're playing a game with a house edge, where winning depends purely on luck, then bankroll management doesn’t really matter.
What you deposit is already intended for gambling, so whether you go all-in or divide it into smaller bets, the reality is that bankroll management won’t change the odds. It just adds an extra layer of stress in making decisions that, in the end, won’t really affect the outcome of a luck-based game.
Well, why does this add stress? It adds an illusion of control to the gambler. If he wants to play for small stakes, then he will do so, if he is crazy today, then he will place huge bets behind his back and lose the entire deposit in a minute. There is nothing wrong with this, because it is their personal money. And it has long been proven that in our human nature there is a desire to have, albeit an illusory, but a choice. This was shown perfectly in the movie Matrix. And this psychological technique is often used in marketing.