That revolution of open source coding opens up precisely the grass roots effort of competing currencies.

Historically there has always been a dominant currency but there has never really been a true monopoly currency. The residual competition is the intersection where increasing network effect crosses with the costs of monopolization and concentration of risks. There have always been alternatives such as silver vs. gold, barter, and other valuable artifacts used as store of value and in trade (spices, art, etc.).

I expect the same digitally except that open source opens up this avenue of alternatives and experimentation to the grass roots and not just a few powerful elites.

EDIT: Also your example of physical gold is not really an argument in favor of bitcoin because gold does not have a fixed supply and also has a supply that is responsive to technological advancement (correlated with economic growth). Bitcoin might be great sound money or it may not, and arguments for either are based on theory. Theory works great until facts on the ground differ, then the theory must be reexamined. So we absolutely don't know the answer here.