For the conspiratorially minded, this is a feature, not a bug. The theory is that the creation of the current central banking system was, in part, to wrest power from the growing influence of regional banks back to the megabanks.
It's relatively well known in fact [0]. Once you realize that was the intention to begin with the structure of modern banking starts to make a lot of sense.
[0] https://www.federalreservehistory.org/essays/jekyll-island-c...