It’s just a very small increment so it’s more useful than ounces for me (maybe this goes back into the whole study abroad thing, although I never did that).
And even though it’s all liquid, I find it a lot easier to measure by weight than using a measuring cup or jigger.
Especially if making fresh espresso, I’m going to dial in my shot by weight anyway so I don’t make bitter espresso. So I’ll have a cheap scale that is accurate within 0.01 grams at the ready.