“Perfection is achieved not when there is nothing more to add. But when there is nothing left to take away.”
It is relevant in so many contexts in life.
If one were to apply it to life in general, it seems even less fitting. Although we can never achieve perfection, I think most people would agree that a meaningful life is lived through growth and gain towards a particular ideal or goal. The more we grow, the closer we come to that unattainable perfection. Removing what's harmful or a hindrance is a part of this, but if all you do is take away and not add, you just end up with nothing.
Ultimately, I think it's lacking because while you can err both due to deficiency and excess, it only considers excess and denies deficiency. It serves more to assuage feelings of inadequacy in the face of unattainable perfection than to give an accurate representation of life. And even if you don't believe in perfection, this quote doesn't deny that it exists, it merely claims that it can be achieved solely by treating excess, while ignoring deficiency.
I'm sorry if this is all very pedantic.
You may not be able to remove anything, but that doesn’t mean nothing needs to be added, ergo it’s not perfection.
It is not unlikely that a decent number of the intended audience will have grown up that "perfection" is equated to having everything, with nothing left to want. New parents especially would have feelings of inadequacy when they are trying to be "perfect" for their kids.