Svelte knows about Typescript natively (you can even use it in the template! Not possible back then), CSS became more powerful and Tailwind appeared, making less/scss/typescript preprocessors not needed anymore.
And many preprocessors are better served as Vite plugins anyways.
So we rethought our assumptions and realized we don't need the config file anymore.
We can use Vite's resolveConfig method to do the heavy lifting of transforming a file path into a vite config object, then check if our plugin is in there to get the options from it.
We still fall back to svelte.config.js if we don't find anything (maybe you don't even use Vite).
We've encapsulated this logic into a small package which language tools use, and you can, too.
www.npmjs.com/package/@sve...
Svelte is among the best-stewarded projects I've experienced, as a very-online open source tech observer over 15+ years
The always-improving design is a treat. Async integration and remote functions are elegant, and recently {let/const, vite.config.ts eating svelte.config.js, and much nicer env. !!