There are more benefits:
Costs nothing to change colors. This makes it great for iterating.
No bandwidth costs as CSS is rendered on the client.
Infinitely scalable in size. No rasterization.
Availability of other CSS functionality, like shadows, animation etc
Re:The Shapes of CSS
by majormajor on Saturday May 26, 2012 @02:54PM
(#4028030)
The last one is an issue, actually. The space invader one is the extreme case: it's already a shadow. And the border tricks for triangles are also shadow-resistant.
I guess one of the cooler applications of this shape making method would be the ability to transform one shape into another very smoothly with a relatively small filesize (as opposed to an animated gif).