Yes, they run it - but for most it is melted into another bundler like PostCSS. The few of us who try to resist the "just use bundlers for everything and everyw

Yes, they run it - but for most it is melted into another bundler like PostCSS. The few of us who try to resist the "just use bundlers for everything and everywhere" do notice that there is now a bundler process firmly anchored in your development process. And yes, being able to jettison a pre-processor for frontend things is a very necessary thing, and unless the designers have accounted for this (I only know of create-react-app having a "jettison" feature, and then - just) you are in for a heap of fun if you need to resurrect a 5-years old app with its dev environment.