Bitcoin is decentralized. That's not a bug, it's a feature. If you create a "Bitcoin bank" the whole "decentralization" concept goes away, so I don't think that would be a very good idea.
Precisely. This idea has been forwarded before and the main reason why it can't be done (or at least nobody is seriously thinking about it) is because that would have been an anathema against the very foundation concept of Bitcoin. Bitcoin is not a corporate entity that would be fighting all of its competitor in the global scale...this is a very different 'beast' that is really unique on its own something that has never been done before nor existed in any form.
However, nobody can stop anyone to put up a bank of his own that can accept and work with Bitcoin and that idea can actually be good. In fact, there had been some ICO projects presenting that kind of idea though they may have their own version of cryptocurrency but may still be integrating with Bitcoin as is customary with all the other coins or tokens we do have in the market.
By the way, welcome to the forum. I understand that this is your first post and rather than asking non-sense post you preferred to make a good reply.