I would say that that C# code that can get 2x-5x reduction in size by being rewritten in JS is terribly bloated (not taking into account the case where you just remove code because there is now a library available for what you had to do yourself before).

yeah javascript is pretty short. unfortunatly I do not know how people love it. npm/yarn and javascript dependency management is the worst thing i've ever seen and it is slow and pulls in millions of files, just for a small project.