When I was writing my comment initially I wrote a comparison between individual crypto wallets and cash, and how centralized banks spawned from people not wanting to be the only one responsible for their large amounts of cash, hence banks, but I removed it because my comment was already running long. We're totally on the same page.

Edit: Also, I know cash is the governmental evolution of bank notes which didn't exist before banks, and that the original decentralized currency would be like, pinches of gold or whatever.