I don’t work on Rome and haven’t looked at their code much, but if I were to guess: performance and better error messages If you can do the same work in fewer

I don’t work on Rome and haven’t looked at their code much, but if I were to guess: performance and better error messages If you can do the same work in fewer passes, it will often be faster So instead of every file change, webpack runs its own parser, then Babel runs its own parser, then ESLint, etc — Rome probably just runs the parser once and sends the AST to other plugins And then if you invest in making the parsing stuff really good, that makes the linter better, the Babel-equivalent better, etc