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.
Honestly, I have a point here in what you said, op, that's what the house edge is really like in all casinos for their gamblers. Then most gamblers also rely on luck when they play in gambling casinos. Then it's also true what others say that when you play slot games, it's really more on luck for anyone who plays in this category.
I just don't know if it's true what other gamblers say that with a small amount of bet you can win a big amount, the usually minimum bet is around 0.2$, with this bet amount the luckiest
I've hit here seems to be around 160$ but the one I know who is around 0.5$ to 2$ tells me that when he gets lucky, he wins 800$ to 1000$.