I'm of the opinion that if you're good at what you do, you should be able to eyeball all the ingredients. You shouldn't need exact measurements to be able to tell if you're using enough if you know what you're doing.
Of course, very experienced people made the recipe by eyeballing, but there was probably still trial and error to get to the desired result. But I don’t have time for this when I’m trying to bake a birthday cake for my son.