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.
Bankroll really matters except you want to be doing monthly contributions to the casino. If I have $100 for example to use for bet which is for the whole week, I can decide to bet $10 for all of my games I will be playing, if I won or lose the amount that I used for that day doesn't change the rules of my wager, I wouldn't add anything until the next day, if I win I will withdraw the profit and make use of the remain $10 to bet another game until the next day.
Gambling with bankroll helps you to manage your funds, helps you from not getting addicted, helps you to control amount you use in gambling. Imagine that you have $100 for a week and then you decided to use everything to bet for that day and lose, where will you have money to gamble the following day. You will be tempted to make another deposit and these are the things that add to gambling addiction, you need to set limit and boundaries to your gambling.