I think YouTube just defaults to a lower resolution (was like 360p in auto when I opened it) maybe because it's mostly text (cause I noticed that too), but you can change it to be 1080p on the settings cog on the video.
Most official Rust projects are dual MIT/Apache licensed by convention [1] (and most Rust libraries from third parties I've seen that are open source MIT follow the MIT/Apache dual license), so seems like this library shouldn't just be AGPL for a typical political choice of a Rustacean?