Funny story, "protein" in Dutch is just "Eggwhite".

So, I was looking for egg whites, for baking. The brand switched from a bottle to a carton, so I couldn't find it. I asked for it, and after the someone pointed it out to me, another shopper goes "You can just buy egg whites? Then why are we buying extra protein bread?" to their friend/partner/whatever.

And indeed. Why are you, random stranger?