Spyro's skyboxes, too. (+vertex colors for LoD models)
I think vertex color can be used even more extensively for modern indie dev, though I haven't done much more than tinker with the workflow itself.
I tried adding non-mapped textures (including a watercolor speckle image) but am not sure I like the effort/tradeoff-to-result ratio*. I'm leaning more towards textureless now especially with Godot 4.4 having per-vertex shading (though I already ran into an issue where it seems metallic per-vertex isn't ready yet).
* aside from maybe generated noise for a metal material's normal map