There is viability to what you're saying but there isn't legality. It is illegal to practice commerce outside of FRNs. We can hold other money like gold and silver, but we can't actually use it in everyday life because the government doesn't want us to. Private currencies are 100% viable and would be one of the best ways to fix our economy, but super criminals don't want that. So they force us to use their currency that they can control.
Free Markets 101 is competitive money. We don't have competitive money. We aren't even allowed what to choose for money. We have algorithms in places to strip us of our wealth through inflation via the Fed. So yeah, we can buy gold and silver and protect our purchasing power, but we can't actually practice commerce with it and do away with the parasites completely. We need to change the laws to allow us to legally use whatever form of money we want. This way our energy will not be stripped of us through inflation and deceptive banking practices practiced by our super criminals.
Gold and silver is easy to use. You have a bank that issues receipts for gold and merchants accept these receipts for payments. Kinda like how Visa and Mastercard are accepted. In this example Visa would be a private bank and when you buy something with your Visa card it would take that money out of your individual account. There would be a few main companies that everyone uses, say Visa and Mastercard, and there would be room for other banks to grow a userbase depending on the needs. We don't need to carry gold coins. It can be done how it is now with credit cards. Except the credit card isn't hooked to a government regulated bank dealing in controlled, Federally-issued fiat currency; it is hooked to a private company that holds your gold physically in their secure location. Merchants choose to accept your payments because they know the banks, Visa and Mastercard, are good for their money. They know that these guys don't inflate their currency and that they don't do all the BS the government does. If Visa does start inflating their currency people switch to Mastercard. If they both start inflating people switch to another one. The most honest and highest quality company will inherently always be the most popular and most accepted. Right now we can't opt out of using inflatable fiat provided by our government. With private money we could.