Why should they?
The 1929 stock-market crash happened under a gold standard.
The Panic of 1870 (or so) happened under a gold standard.
Along with several others during the 19th century.
You mean, aside from the ‘old’ Constitutional thang (IE: no authority to delegate, let alone specifying gold/silver. Or that the Fed note, in ~100 years, had ‘depreciated’ by 100% (ah, but like most things gov’t there WAS a time of ‘equal swap’ (silver certs))?
Lastly, I think your first example is moot...happened AFTER the Fed act (and though many would say caused by the same, just proves that even they had no gumtion/ability to ‘stop’ the crash either)