2D vs 3D portfolios: what does each one actually prove?

I was looking at some 3D character artists' portfolios recently and noticed something. Their work communicates an understanding of form in a way that's almost impossible to fake. Every angle holds up. The silhouette reads from any rotation, not just the one carefully chosen hero shot.

That got me thinking about my own 2D concept work. I can suggest volume with value structure and overlapping shapes, but honestly, sometimes I'm solving a flattened version of the problem. A 3D artist has to commit to how a form actually wraps in space. A 2D artist can imply it and move on. Neither is lesser, but they reveal different kinds of thinking.

The thing that finally clicked for me was that studying 3D artists' turnarounds made my 2D silhouettes way more convincing. I started thinking about the back of a character's head even when I was only painting the front. It changed how I block things in.

So here's the real question. When you look at a portfolio, does one approach reveal a deeper understanding of form and problem solving to you? Or do they just prove different things entirely? Curious what people here have found.