"We will charge you $1 for checking your account's balance."

Ahh yes. The Automatic Tip Machine.

In Australia. We basically had this for a long time. Charged fees to use atm’s, unless the atm was specific to your bank.

Then basically at some point the banks realised that it was cheaper to just refund us those fees, rather than maintaining their own ATM’s.

No, not Bitcoin or crypto. Those are currencies but don’t provide financial services.

They're not even currencies. Most people buy them solely to hold onto them, not to spend.

In theory, you could have open source bank software. Security by obscurity isn't security, after all. If the only thing keeping you safe is the code being closed source, you're not actually safe. Attackers will find exploits even in closed source code (just look at how many Windows exploits there have been) and attackers may get access to source code anyway. However, I think you might have a tough time convincing the average person of this, based on how I've seen folks react to open source in the past.

Above all, the kinds of people who love FOSS and the kinds of people who want to run a bank are probably two completely separate circles. Heck, banks seem to regularly have terrible security, actively breaking best practices.

If someone develop a malware from open-source bank systems, then the economy will probably crumble in just few seconds (lol). I don't think FOSS banking system will contribute to poorer countries where most of their transactions are done with cash. It always starts on tech literacy from FOSS enthusiasts.

It's subtly happening already.