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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.
Actually, if we talk about casino games (ignoring for a moment sportbetting), bankroll management is the only factor in our session on online casinos we can control as gamblers, because the seed and entropy are completely random and outside of our reach, that is something not all gamblers understand, specially those we are new in this ecosystem.
Anyways, we should also be aware bankroll management is not about managing our money to get profits from the casino or something similar, it is rather a way to extend our session and make our money to last longer so we can have more fun and thrill with the same amount.
In the long term, the casino will take it all, as it has the house edge on his side.