Yes, that's true. But inflation did occur under the gold standard. So did deflation.
It is true that every single paper currency in history has utterly failed, not a very good track record.
The dollar hasn't utterly failed.
Surely you cannot argue that paper money has a good track record. The point still stands. Also - consider for a moment that, back in the day you were to counterfeit gold coin in your basement. It was at least .900 fine, as pure as the "real" stuff. Visually undetectable. Nobody would have cared. In fact, that's how the US mint used to operate. You broughts yer gold to the mint, and they gave you coins back in return. Gold has a certain fiat value as well, as governments have almost always used seignorage. Contrast that with running your own printing press. THAT will invoke the ire of authorities. Ever wonder why? I'm using the same paper, the ink - no one can tell! So my argument is not necessarily for a metallic money standard, but some form of sanity and rationality to "money". In some ways I believe cheap money begets cheap people.
"Inflation did occur under the gold standard"
That's the econ 101 view, but the reality is different. It's OK to have different opinions but it's not OK to be wrong in the facts used to make up those opinions. The "price" of gold was ~ $20 for a looong time, roughly 150 years. Personally I don't care one iota whether we are on a "managed money" standard or whatever, only that there is a standard for the unit of account. Gold held that standard for several thousand years since it was A. relatively rare, and B. not easily counterfeitable.