> I think they should be free to figure out among themselves
Why should it be normal or even ok for bankers at competing banks to come together to "save" another bank (more specifically their depositors)? That seems like a recipe for a cartel in any other industry.
> I have no problem looser regulation but I believe it comes with greater responsibility.
This seems non-sensical to me. You want some set X of measures to be respected, but you don't want that to be explicitly enforced by government regulations - why exactly? If that set X is important, then why not make it explicit and directly enforceable? If it's not important, why should bankers be held responsible if they fail without following it?
I think it's pretty clear that the proper way of doing this would be to have official government regulation + official government guarantees for depositors at any bank that follows those regulations + actual enforcement and verification of those regulations. And any regulated bank failure should mean additional regulation to prevent those failures, similar to how the airline industry (used to) operates.