Earlier quoted context omitted.
While keeping something running via an informal system is better than nothing, and most people might be okay... if you're just kinda shifty looking or unpopular at the moment in your local pub and have a much harder time than everyone else, that's not exactly great. That is, it's not only the common experience that matters, but the outliers too. The basic tools of society should be available even if you're ugly, anno…
This problem is far worse with a concentrated system than a decentralized one. If there are five local pubs and one of them won't have you, well, still four more. If there is only one bank and their loan officer doesn't like the cut of your jib, or their algorithm has decided to have a false positive, you're done. Though of course the modern problem isn't that there is only one bank, it's that there is only one bank…
They can break in different ways. If you're in an out-group or unpopular, it's not clear whether you're better off with n local pubs making a decision to accept your money informally or n/2 national banks making a decision while subject to oversight.
In any case, this is a false premise: it's not like you're choosing from 5 local pubs. The question is whether the pub you attend likes you enough to take your check.
> What you need for this is something permissionless.
Far better to have things work okay without any other entity being involved, sure. But there are reasons why banks exist.