Is it ever more accurate to measure by volume rather than by weight?
Better is a subjective term, however you can see what is done in practice as a guide to what people think is generally efficient as a balance of preparation speed, accuracy and cleanup. 

Many recipes use a combination of volume and weight. Volume for most liquid measurements like milk, water or stock is considered more efficient than weighing them because although weighing is more accurate in most recipes the differences are small enough not to make a difference. 

Weight is generally considered more efficient than volume for larger quantities of dry ingredients or gels (butter, lard, shortening) as it's faster, more accurate, and less cleanup. 

Small amounts of wet and dry ingredients like spices, herbs, powders, flavorings etc are usually measured using volume measurements like teaspoons and tablespoons. I've tried it both ways and I've found that using teaspoon fractions is much faster than trying to weigh out small amounts of ingredients, and that my scale isn't accurate enough to weigh the fractions of grams you'd need to get that level of accuracy.