I think that nothing life-changing is actually going to happen. We have already been there.
While what you say sounds logical can you point out where in your "been there logic" things were decentralized?
Actually, they were completely decentralized "there". When it all started back then, any bank could issue their own "money". Bills of exchange, bank notes, certificates, depositary receipts, etc ad nausea are all examples of "private" money. So you had many options open
how to lose your gold to pick up from..
Or you could just keep your gold and were immune to the inflationary effect. Of course paying with gold was difficult, keeping your gold safe was also difficult. Bitcoin however makes paying direct with Bitcoin easy. There is no need to put you Bitcoins in some bank which will issue fiat currency using it as a reserve. Of course you are free to CHOOSE to do so but others are free to not. If these fiat issued currencies end up inflationary well it will make people less likely to choose that option.