I have several of these small 29.6cc scoops, which is 2 tbsp or 1/8 cup.
And a 1/4-cup measuring cup which is also marked in ounces and tablespoons and milliliters.
I don't use those big scoops for measuring powders. I don't use bottle caps for measuring liquids.
It's more accurate for larger amounts to do multiple level-fills of a smaller-size scoop or cup than to eyeball a line that's essentially invisible in a colored cap that's typically opaque.