Cynical prediction: by the time this project is finished, the entire rendering of browsers happens in the GPU.
Parts of Servo to enable the use of the GPU for compositing layers were merged into Firefox years ago.
https://hacks.mozilla.org/2017/10/the-whole-web-at-maximum-f...
It's a shame that Patrick Walton didn't get a chance to finish his work on the Pathfinder GPU renderer.
>Pathfinder 3 is a fast, practical, GPU-based rasterizer for fonts and vector graphics using OpenGL 3.0+, OpenGL ES 3.0+, WebGL 2, and Metal.