I don't know that we need preprocessors even today. There's a case to be made for their use and there still we be in the future - but it's pretty easy to author and ship vanilla CSS without requiring any extra tools! I prefer to write vanilla CSS because it's the most reusable from codebase to codebase if you're building in a modular way ☺️ Not every project uses the same tools or preprocessors, but I have yet to find a project where vanilla CSS doesn't work exactly as intended.