Gold is not "unreactive". There are a variety of gold compounds:
Au(CN)2, AuCl, AuCl3, HAuCl4, and many other more complex ones.
In addition, there are eighteen gold radioisotopes, so the amount of gold in the universe is decreasing as they decay.
In addition, not all of the gold on earth has been discovered, much less the whole universe. We also don't know how much the ultimate amount might be, so the amount of gold in known existence is not stable.
Regardless, the use of gold simply because of its relative stability of existence is ridiculous. While you might not be able to change its amount, you can still alter the amount of purchasing
power it commands by altering the amount of purchasing
power available.
Gold
standard promoters claim that all
fiat currencies have failed. There are very few countries in the
world that don't have
fiat currencies, and their currencies have not failed, making the claim prima facie false.
Please do your own research into the matter.