alt Hacker NewsSuch is life when built-in laptop displays are now pushing a billion pixels per second, rendering anything on the CPU adds up fast.
Sublime Text spent over a decade tuning their CPU renderer and it still didn't cut it at high resolutions.
https://www.sublimetext.com/blog/articles/hardware-accelerat...
Most of the pixels don't change every second though. Compositors do have damage tracking APIs, so you only need to render that which changed. Scrolling can be mostly offset transforms (browsers do that, they'd be unbearably slow otherwise).