Oakes Spalding has written a post explaining why he chose to use a silver standard in Seven Voyages of Zylarthen, and why it’s a better choice for games.
In the post he explores not only the history and comparison of silver vs. gold, but also provides a rather excellent historical table of currency weights and values that he had developed for another game. Something that he points out is the divergence from OD&D to AD&D 1e in exchange rates where 1 gp = 10 sp = 50 cp in the former, while in the latter it’s 1 gp = 20 sp = 200 cp.
One thing that should be brought up is that this 1:20:200 conversion rate only exists in AD&D 1e. In other D&D games such as D&D Basic, which came out before AD&D 1e, and in the second edition, there is 1 gp = 10 sp = 100 cp conversion rate used instead. This doesn’t of course argue against using a silver standard, but for other games the 1 gp = 10 sp rate is much more the norm than what seems to be the anomalous 1 gp = 20 sp in AD&D 1e. If realism with historical accuracy is what is required then switching to using a silver standard may work just fine, but for the most part using gold vs silver as a standard is something that can be aesthetically and mechanically overlooked.