The icon is 1024 x 1024 pixels. At ten times smaller it's maximum size would be about 102 x 102 pixels. That isn't enough for Quick Look or full Dock magnification on non-Retina Macs. Never mind the MacBook Pro with Retina screen which requires (off the top of my head) 128 x 128 pixels for the default icon size in Finder. At 205 x 205 pixels you won't have enough to support Dock magnification on said MacBook Pro with Retina screen either.
That large icon example is about 10 times bigger than a large icon should be, at one fifth of that it would still be more than big enough for any icon usage.
I meant is it feasible for the OS to render an icon that detailed as a vector? The more details a vector image has the longer it takes to load in Adobe Illustrator (per example). I imagine something similar will happen within the OS when you have to load a complex vectorized icon. That said Adobe Illustrator isn't exactly fully optimized for today's hardware, so maybe it's different in software that is.
Feasible? Sure, why not. It's all up to how much time and skill you have when drawing your icon set.