At one point I might have agreed with you, but after working on a few sites of my own I found that Javascript just enables a vastly better user experience. No need to refresh the page every time the user does something like liking a post or sending a comment, can load content more seamlessly with pre-loading or lazy loading, enables expandable menu bars to maximize space for content when the menu's not in use, things can be loaded faster and with less data usage if you send page diffs instead of full pages of markup, etc.
Javascript's terrible when it's used to generate pages from bloated frameworks that create 5000 DOM elements, add listeners to everything, load a dozen external scripts, and so on, but it's really valuable when used to actually improve the user experience.
