Hadn't thought about it but it seems to be true here in the States too. Many things (soda, etc.) have moved to metric units but dairy continues to be imperial units.
Exception: Ice cream, which has been suffering with shrinkflation for years. Used to be the half-gallon was the standard unit of measure, but then they went to 1.75 liters, and lately 1.5L seems to be the new norm. It's getting so that eating an entire carton in one go isn't even embarrassing anymore.
It's 2 litre & 4 litres for ice cream in Oz!
The fancy brands go down to 750ml.
Milk comes in 1 litre, 2 litre & 3 litre, & the rarely seen 600ml.
Flavoured milk drinks are normally 600ml, on the other hand, although sometimes you see 300ml.
Some years back, Nescafe changed their large can size from 500g to 400g.
"Great!" said the big chains, rubbing their hands together!
It went over like a wrought iron hanglider, & after a few months, Nescafe quietly restored the 500g.
That was it, as far as I knew, until I was in Aldi one day, & spotted cans of Nescafe for around the same price as Coles & Woolworths sell 500g cans for "on special".
As this purported to be a "everyday" price, I grabbed a couple, & was congratulating myself on a good deal, till I noticed "400g" on the label.
Now I knew where all those unsold 400g ones went!