为何jQuery核心文件未被主流浏览器默认内置？

Great question! Let's break down why jQuery never became a default part of browsers, even though it was one of the most widely used JavaScript libraries for years.

• 原生API的快速追赶
  jQuery blew up mainly because it solved the massive cross-browser compatibility headaches of the 2000s and early 2010s. Back then, doing something simple like selecting elements or making an AJAX call meant writing different code for IE, Firefox, Chrome, etc. But over time, browser vendors got serious about aligning with web standards. Today, native APIs like document.querySelector(), fetch(), and Array.prototype.forEach() do almost everything jQuery used to handle—often more efficiently. There's just no need to bake in a wrapper library when the native tools are now reliable and consistent.

• 体积与性能的权衡
  Even the minified jQuery core is around 30KB. For browsers, adding that to every page load (whether the site uses jQuery or not) would bloat the baseline resource overhead. Modern web development prioritizes speed and minimalism; forcing all users to carry extra code they don't need goes against that ethos. It's better to let developers choose to include it only when their project actually requires it.

• 版本迭代与灵活性限制
  jQuery has had dozens of versions over the years, with API changes, bug fixes, and new features. If browsers shipped a specific jQuery version, they'd be stuck maintaining it—or forcing all developers to upgrade when the browser updates. This would take away the flexibility developers have to pick the version that fits their project's needs (like supporting older browsers with jQuery 1.x, or using the latest features in 3.x). Browsers don't want to lock developers into a specific third-party library version.

• Web标准优先的原则
  Browser vendors focus on implementing and evolving official web standards, not third-party libraries. jQuery is a layer built on top of native JavaScript and DOM APIs, not a standard itself. Building and maintaining a third-party library as part of the browser would divert resources from improving the core platform. The goal is to make the native web platform so capable that libraries like jQuery become optional, not mandatory.

内容的提问来源于stack exchange，提问作者mudraya