jQuery was, for the better part of a decade, essentially the default way to write JavaScript on the web — its rise and fall says a lot about how browser standardization can eventually make a library obsolete.
Why jQuery Took Over
// jQuery in 2006 solved genuinely painful cross-browser inconsistencies
$('.button').click(function() { $(this).addClass('active'); });
// The vanilla equivalent at the time required browser-specific branches
// for attachEvent (IE) vs addEventListener (everyone else)
Why It Faded
Modern browsers standardized the APIs jQuery originally existed to paper over — querySelector, fetch, classList, and consistent event handling are now natively available everywhere jQuery once mattered most. Meanwhile, component-based frameworks (React, Vue) offered a fundamentally different, more structured way to build UIs that jQuery’s imperative DOM manipulation style didn’t fit into cleanly.
Where It Still Lives
jQuery remains deeply embedded in WordPress core and countless legacy enterprise applications — not because it’s the best current choice, but because ripping it out of a decade-old codebase is real, costly work that often isn’t worth the risk for a purely internal tool.