There is a whole article comparing Nyxt to plug-ins (such as tridactyl): https://nyxt.atlas.engineer/article/nyxt-versus-plugins.org
I'm actually hoping tridactyl will follow neovim and embrace js more (similar to lua in neovim).
So not a great sales pitch for me specifically, but still sounds like a step forward for turning browsers back into user agents for power users and programmers.
We already have `:js` and `:jsb` along with a few commands that accept JS callbacks :)