This applies mostly where there's almost no proper and strategic fund management strategy, that is the only time we can relate that the bigger the bankroll the bigger the loos that will be suffered by the gambler. For gamblers who are really disciplined enough to be able to handle situations as this they may not get o suffer such with their big bankrolls because at this point to they are gambling to make money so they make sure they are more careful and are now doing even much better and are been able to grow their bank roll so their picks are minimal and more careful.
Sure, bankroll management is very essential for a gambler and any gambler that doesn't know how to manage his bankroll will run at loss because he will not be a disciplined gambler and would not know the right time to stop his session until he loses all his bankroll. Back to the topic, excessive bankroll can lead you to addiction, because you will over do it.
Yes, there may be some people who ask about why gambling should be done with a very careful and considered approach, and I think some of us already know that one of the reasons why money management is something that must be involved in gambling is because no matter what and whenever gambling will always be a risky activity, the biggest reason is because there is no certainty and guarantee that you will always be able to win while when you don't win it means you lose and lose the amount of money you bet.
You have said about what will happen to a gambler when they do not know that gambling must be done by implementing very good money management, none other than the goal is only one, namely to minimize the possibility of losing a significant amount of money.