Why don't more developers "use the platform"?

Developers often bypass native browser capabilities in favor of third-party libraries and frameworks due to historical reasons—browsers were slow to implement features, making custom solutions necessary—as well as familiarity with existing tools like npm packages and React. Additionally, third-party libraries have traditionally offered better documentation and more user-friendly abstractions than platform APIs, creating a self-reinforcing cycle where developers default to familiar ecosystems rather than native browser features, even when those features are now robust and performant.