To stay at home or not to stay at home...that is the question

I have been going to Gymboree class every week with my current charge and I realized that I am the only nanny. I found myself discussing my child's situation with one of the moms and it occurred to me that it seems very abnormal to people outside of our circle. My charge has 4 care givers, a mom, dad, nanny and adopted Chinese grandmother. He sees me 50 hours a week, the Chinese grandma 20 hours a week and then his biological parents fill in the blanks wherever necessary. The mother I was speaking with was appalled at the thought of leaving her child to be raised by someone else, after all, she brought him into the world. Then today a random thought crossed my mind, this is the most critical time in my charge's life. There should be someone with him all of the time giving him one on one affection and teaching him life's lessons. Pretty soon he will be going to pre-school and then he won't need me anymore. He won't even remember that I was there and not his mommy; it will be mommy greeting him after school every day, not me. So does it really matter who does the dirty work now? As long as he is getting the most love and quality care?