If a bank doesn't know what your currency is worth compared to any other on a standard rate, they can't convert it. Which means, you can't use banks. That means you have to set up your own banking system.

Seeing how their primary goal is to dismantle any and all banking systems that they don't own, no bank will be around to deal with your form of currency and as such people will simply not use it. What you say is true, which is why they have acted to destroy any and all banking systems aside from theirs.

The rules/traditions are stupid, I agree. That people follow along with them is the reason we're in such deep shit. They are con men, simple as that. They are using our own good nature in assuming they aren't trying to control us against us.

Remember what Jesus said about Caesar's currency?

Give to Caesar what belongs to Caesar, give to God what belongs to God.

It's a resonant message with several deep meanings, but the sum of it is that we shouldn't view currency that has another man's face on it as our property. Doing that lets them have power over you. The only one you should let have power over you is the one who made you who, fortunately, is also the one who is willing to die for you.