There are broad gauges other than 1600 mm, just not in Australia...
The English Great Western Railway was built to a gauge of 7 feet 0 1/4 inches, substantially more than standard.
It did provide significant technical advantages in 1835.
By 1892, it was realised that a common gauge was more important and the line was converted to standard gauge all the way from London to Penzance over a weekend. Quite a few locomotives had been built to be suitable for conversion to standard gauge, at least partly because developments in design allowed standard gauge locomotives to equal the performance of the older broad gauge locomotives.
One result of the GWR broad gauge was larger clearances that allowed slightly larger passenger carriages than elsewhere in the UK, but since most vehicles had to run on other railways, this was not taken advantage of.
In Australia, the broad gauge clearances were almost the same as those on standard gauge. When the Spirit of Progress ran through to Sydney, only the handrails beside the doors had to be altered. After a few years, an unaltered broad gauge car (on SG bogies) ran through and it didn't hit anything.
Sydney's suburban trains had larger clearances from the start of electrification than Melbourne, and these were taken advantage of by the double deck cars. The modified Tangara built for Melbourne was lower and narrower and could only seat four across rather than five on the lower deck.
So it might be said that the VR did not take advantage of the wider gauge since their clearances were the same or smaller than standard gauge.
Had either or both gauges in Australia had significantly larger clearances in height and width, like the USA or Russia, that would have remained an advantage. The narrow gauge doesn't permit taller vehicles, although Queensland coal hoppers are actually wider overall than those in the Hunter Valley, but the narrower formation limits axleloads to less than the standard gauge.