If you get it right in bankroll management that means that you are qualified to be called a responsible gambler, it takes self control not to be lost in gambling and deplate all your bankroll funds within a short time. As OP noted gambler should pre determine how much they are going to use to gamble before they start, the decision will help them to be disciplined to stop when the amount is finished. No need to refill to chase loses, just stop when the budget finishes, even when you are winning try and stop when budget for bankroll finishes. It is easier said than done for most gamblers but practice and determination will help to increase self control.
You said it all, bankroll management is the step to be qualified to be a responsible gambler, but this is hard to achieve because you would always be tempted to chase your losses at so point and if you are not well disciplined you will fall for this. You can set aside an amount of money that you would use to gamble and plan not to go beyond it but when losses starts coming in without discipline your plans might change