FI, I think you just described essentials and statements exactly, and described how they work together and why both are needed to make a wardrobe and outfits work.
While I love an all essential outfit, notice I said "the right set of essentials." It's very hard to find essentials that aren't merely dull, that do have that right cut, good fabric, extra texture, and excellent fit. If even the essentials have that, then they elevate all my outfits, even if they're not the center stage items.
If I'm going to wear an all-essential outfit, I have to choose the items, proportions, and colors carefully, or it's merely dull, and I feel frumpy rather than striking.