If you’re used to cups and teaspoons of course you’re more likely to use binary divisions. I’m more likely to use steps of 20% for that purpose. And if you want to actually tailor your proportions to match the one egg or whatever the indivisible object in your recipe is, then you end up with 241 mL or 13.57 Tbsp anyways. Anyway, ten isn’t the magic number, it’s just the one we use for almost everything, and already did when we had imperial measurements.