Comment by inigyou

I don't think this is any better for power efficiency? You're taking the modern system as an axiom, which it isn't. The old system didn't "deliver frames at" any specific rate. The graphics chipset sent to the monitor whatever was in the framebuffer at a specific rate, and windows updated whenever they wanted to. The text editor didn't "deliver frames at 144Hz" or any other Hz - it updated some of the pixels in the framebuffer when you pressed a key.

It cost nothing to not change the pixels when you didn't press a key, no matter whether you weren't pressing keys at 60Hz or you weren't pressing them at 144Hz.