Here’s a big part of why they want 1000Hz. You don’t need to fully re-render each frame for most cases where 1ms latency is desirable - make a 100 Hz (or even 50 Hz) background and then render a transparent layer over it.
Here is an alternative Piped link(s):
Here’s a big part of why they want 1000Hz
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.