Well, yes…there really isn’t a single one of these supplemental protein sources that has everything in ideal quantities…whey, casein or collagen etc. Using a protein smoothie after my early am home workout session is really in lieu of my former fave breakfast of whole grain muesli breakfast …with I’d wager single digit protein content. Whey is particularly useful in this context for its fairly rapid absorption.
It’s a good point to make, though, when considering just how much of a replacement these supplements might make to a regular diet.