I feel like it's a win by default. I do like to write my own programs every now and then and recently there's been more and more graphics sprinkled into them. Being able to reuse those components and just render onto a target without changing anything else seems to be very useful here. This kind of seamless interoperability between platforms is very desirable in my book. I can't think of a better approach to achieve this than the graphics API itself.

Also there is no inherent thing that blocks extensions by default. I feel like a reasonable core that can optionally do more things similar to CPU extensions (i.e. vector extensions) could be the way to go here.