I totally agree. Using js to replace css is absurd. But in many apps self develop all the code it’s not the more economic way to go. For example I’m building an app that need a complex calendar (like Google calendar). Reimplementing all functionalities from zero will require many ours, instead I’m gonna use fullcalendar.io library. Code and library reuse it’s not a bad thing but a good one. Now we have way to reuse this third part libraries in a modern way (ES modules) without the need of transpile our code. In my projects this speed up dev a lot.