The gold standard and metalism generally, leads to all kinds of unproductive panics bc the quantity of money can’t wisely be adjusted to the situation. It’s a bad trade off, bc it’s well-known in the literature that inflation-targeting works (and that’s the current world-wide central bank policy since 1991).
It also can’t be unwisely adjusted to the situation (usually in the form “too much for too long”).
I tend to think the benefits of unbacked currency exceed the downsides, but it’s not exclusively upside.