Lyn Alden expresses well what killed the gold standard. Settlement is the problem. You can't move bricks of gold around easily. So then you have to do a paper gold on top of this, and now of course its digital, but this of course opens up lots of counterparty risk and you can't verify who has what, etc.The argument is anti-fiat, but in reality it's a maximalist argument as the total crypto-market is approaching $2.5T. I think a better valuation metric is marking it to some multiple of GDP. IOW what made the gold standard impractical. Crypto will experience the same limit (gold standard analog).
With Bitcoin, you're exchanging the actual thing that has value, and there is no backing because Bitcoin just is.
I think most people can't get their head around bitcoin because we have never had all of these properties available in money at the same time. It was never easy to move, and verify, and scarce all at the same time.