In your experience about casinos, have you seen any that show such evidence in the past? That seems like revealing sensitive information that people might learn to evade in the people.
They actually do this on platforms like Casino Guru, the evidence is obviously not reveal directly to the accuser but to the mediator and when the mediators look at it. They can determine if the casino's claims are true or not.
The problem is that many gamblers does not real the TOS of casinos, some do but deliberately chose to be obtuse. Most casinos state in their TOS that they have the right to terminate the account of anyone seen to be violating their TOS of which multiple account is one of. There are various mechanisms casinos us to confirmed multiple accounts and that is not what they can share in public. In conclusion, Rollbit is too big to scam someone of $1,263, that is not up to what they give away monthly in their X account.
The problem is you have not been a victim before, so you think everyone whose account is blocked is a cheat or dubious. Haven't you seen user issues get resolved after creating a complaint here or on those platforms?
I can list 3-5 similar issues here that have been resolve after the user had previously been accused of having multiple accounts. Don't always look at things in black and white.