The number cause of an account getting banned is cheating.
Sometimes even if we don't think we are cheating we are just surprised that our account has been banned, the reason is we don't follow the TOS and because we just sign up without reading the TOS, we are unaware we had already broken some of the rules, so we complain but actually, it's our fault.
However, scam casinos ban you for no reason, they just want to scam, so always consider the reputation of the casino before signing up.
Cheating most of the time or abusing promotions or giveaways because this had been always the case on why people or players getting banned and they do make out some complaints?
They do know on what they have done and just playing dumb and being innocent which do sucks for those casinos who do give out right decisions on making those
players been banned.
Read up the TOS or terms where you usually read up on registration and that's the importance of it.