What he's not telling you is that we had wild swings in the value of the dollar. Swings like 20% up one year followed by 20% down the next that were very disruptive to business.
We had deflationary depressions every 20 years prior to the FED.
Under the FED the value of the dollar is much more stable. The dollar has less than half the year to year variation that it did prior to the FED. However the FED does intentionally err on the side of inflation. And 80 years of consistent low level inflation takes a toll on the value of the dollar. It's not a toll that matters because it's spread out over 80 years. Unless of course you are hoarding cash in your mattress for 80 years.
Currency is meant to facilitate business transactions, not be a long term store of value. If you want to store value for long term, but the money in a bank account and draw interest to offset the inflation, or better yet, invest it in sound companies that will be around for the long term.
So stealing someone’s life savings over their lifetime is just dandy? Thievery is okay by you?
Furthermore, deflationary depressions are NONSENSE! Each of your wild swings (which were no more than 5%, not 20%) were caused by INFLATION of the supply of gold or silver. Check your assumptions: just because you were tested on it in Econ class doesn’t mean it’s true.