I prefer metric to imperial, but if milk changes from pints to litres, it's probably for shrinkflation since they can shrink the bottle from 2.272L to 2L and most people won't notice.
That's exactly what happened with beer. Newky Brown was the last hold out, now even they do 500ml bottles. Some cider still has pints, but I think even they've dropped down.
Milk is litres as well now, depends in the brand though.
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