However, from what I understand, there seems to be two things needed to be noted here:
Skia - a standardised library that can 'render' to different backends - i.e. it can render to OpenGL or SVG or PDFs.
CanvasKit (the actual one linked) - basically use Skia on the web (with webgl).
A huge boon here would be performance. For example, in WebGL, if you want to draw text, the current method is actually to render it in the canvas first, and reupload the texture to the GPU. From what I understand Skia seems to handle the rendering 'natively' so this step is not necessary. So basically it would just make it easier to draw 'primitives' since they are provided by the Skia API without having to do workarounds or writing really low level webgl fragments/shaders.
This is just from what I gathered, but yeah it is confusing. If anyone knowledgeable reads this, let me know if I got anything wrong!