IIRC with default settings, kitty is intentionally slowed down (e.g. repaint delay). You need to override them if you want to benchmark it.

>https://github.com/vivido-dev/vivido

That looks genuinely cursed. What are the practical use cases for video in your terminal? More broadly, I feel like the entire terminal UI world took a wrong turn somewhere, it's clear that it long outgrew the capability of fixed-cell presentation, but there's so much unwarranted bias against GUI that people in it would resort to insane hacks to emulate GUI in a janky way rather than make a sane GUI toolkit. It's the same route as the one web browsers took (documents -> GUI), and will end up the same way.