Many people trying to use 2 or more accounts because they thinks that can help them to win or reach what they want. But that will only gives them trouble so they must realizes for that and will not do that in any casinos.
How come having two or more account help to win more ? More accounts = more to deposit = more to lose, when chance to win is the same for every gambler. I can only understand if the situation was about users trying to cheat with welcome bonuses if there were any. But correct me if I am wrong, nobody now gives free bets or free spins just for a registration. I could understand if a person creates another account, because his first was banned, but it is a risky move, because chances for second account to be banned are increased. I can accept that someone create multiple accounts because he wants to get low level up bonuses, because wagering several thousands is always easy than, for example, wager from 50k to 100k to get free 10$. But that is also illogical. While trying to get $10, it easy to lose much more.
You are right, playing with more accounts at the same time will be the same as using much more money and losing more money, if gambler understands how gambling works with all the risks involved then I am sure they will not do something like that.
Only people who may have been desperate and tried to win more do it, but they will be able to realize that all that was mistake when they have felt the many losses that exist.
But for more precise reason, the prohibition on using multiple accounts or more than one account is about utilizing bonuses, and this can be condition that is detrimental to the casino.
For bonuses such as deposit bonuses and various other bonuses, those who like to hunt for bonuses will definitely complete them even though they are not bonuses that can be obtained for free.
In addition, the existence of weekly and monthly bonuses from VIP accounts is special attraction for those who like to chase bonuses, the requirements vary and of course they will use casinos with VIP account upgrade requirements that are quite easy to meet.