Rio is Fast
Rio is perceived fast, there's few reasons behind the speed. First reason is that Rio is built in Rust ("Speed of Rust vs C" kornel.ski/rust-c-speed). The terminal is also built over ANSI handler and parser is built from Alacritty terminal's VTE github.com/alacritty/vte.
The renderer called Sugarloaf has a "sugar" architecture created for minimal and quick interactions in render steps using WebGPU with performance at highest.