I was under the impression that Inkscape explicitly doesn't follow the gnome guidelines.

That's why every few months, there's a proposal to redesign it which trades usability for minimalism. Here's one I pulled from a random Google search:

https://gitlab.com/inkscape/ux/-/issues/236

https://wiki.inkscape.org/wiki/Inkscape_invariants

They claim it's one of the cornerstones of their project. Who am I to argue.

Personally, I like how functional Inkscape's UI is AND how minimal Files is, for example..