Design-wise it looks cluttered af even for a thing that is supposed to be intentionally light. How am I supposed to differentiate users in such setup? Looks like hell to me.
The idea is interesting, though, and I like that it's written in Rust as well.
Having a "brutalist" aesthetic is called out in its README as part of the design philosophy.
Brutalist is a bit of an acquired taste. There are at least a couple different schools of brutalism (this one seems to line up with more of a 90s web aesthetic), but I like to think of it as a kind of intentional ugliness that allows designers to emphasize practicality. You're there to participate in the content, not the pretty boxes around the content. (I dunno if I'm explaining it well or not.)
I feel like just a few margins would still keep it "brutalist" (e.g. using HN as a reference, which is often labeled as an example) and improve it a bunch.
The idea is interesting, though, and I like that it's written in Rust as well.