Gold is far more volatile than fiat currency. Commodities are subject to abrupt changes in supply and demand. There's a reason why both William Jennings Bryan and Milton Friedman thought the gold standard was a terrible idea.
The reason William Jennings Bryan thought the gold standard was a terrible idea is because he wanted a currency with higher inflation than a gold tied currency could deliver. 'Free Silver' ring any bells? Seriously, pretending WJB had objections to gold for academic, reasoned economic stability reasons is silly.
No gold standard in the 1920's is difficult to achieve. It took the Great Depression for the American people to be OK with breaking the golden fetters and the American economy in the aftermath of WWI was in a position to dictate monetary policy to the rest of the world. That is WHY the inter-war gold standard was a gold exchange standard, with gold and
American public securities tied to gold making up the international exchange medium. The Americans were owed large debts from other belligerent powers and wasn't about to accept anything but gold or trusted (read: the aforementioned American public securities) in payment.
More broadly, there was no alternate framework for the victorious powers to work from. The gold exchange standard was a radical new thing that was kind of made up as they went along (which is why there were so many conferences on the international monetary system and German reparation debt -- which was intimately tied up in the former -- over the ocurse of the 1920's), they wouldn't have any clue what to try to put in its place. Gold was the natural thing to try to go back to: Creditors trusted it and creditors dictated a lot of state financial policy in this period.
Even if you handwave away the challenges of achieving the policy, I don't think that things would have turned out dramatically differently. There is a truism that you
either have a gold standard
or an activist central bank, you can't
really have both, in practice. All of the powers in the 1920's had activist central banks, the gold exchange standard only really resembled the automatic mechanisms of the pre-war gold standard at a distance, while squinting. I think the central banks in question would have acted in more or less the same ways, for the same reasons, leading to many of the same consequences as IOTL. Modern ideas about monetary policy didn't exist at the time (or were in their infancy -- this is the age of Irving Fisher, monetary economics-as-modern-science was
brand spanking new at this time; monetary economics-as-monetary-policy-guide wasn't on the radar). They couldn't conceive of alternatives, they hadn't been invented yet.