Honestly, my favorite explanation is that gold currency is a ponzi scheme that forced the roman empire to conquer more and more gold bearing land until its territory was so large that it was difficult to defend while simultaneously invading new territory. The moment they failed to conquer an ever growing mass of land, they had to pay the army while all the wealthy people have hoarded gold and kept it out of circulation which destroyed the medium of exchange function of money and therefore forced Romans to issue additional coins with less gold to pay its soldiers as hoarded gold coins do not pay any taxes.

Most people interpret inflation as obvious government mismanagement, I interpret it as an inevitability because of the inherent conflict between medium of exchange and store of value caused by using gold as currency.

Saved money that is used as a store of value interrupts the circulation of money which then stops the payment of taxes which then forces the government to find a substitute for the loss of tax revenue. The answer is to separate the medium of exchange and store of value function into two separate "institutions". Cash is not a store of value, banks delegate the store of value by giving loans to producers of value i.e. companies and entrepreneurs. If you just save cash/gold, there is no guarantee anyone is going to produce value in the future. You are basically speculating that there are going to be people in the future that will gladly take your gold and then people act betrayed when that speculation didn't pan out.