Web development is a bit like runaway sexual selection, but instead of developing extravagant plumage, webdevs develop extravagant frameworks and strive to rewrite everything in JavaScript.

Blog posts are a way of status signaling but also of fitness signaling. People that have the capability of always learning new things and writing about them should be really good programmers while lower quality individuals can't afford to keep up and drop out of the game. Only the former are able to reliably secure mates and reproduce, thereby perpetuating the cycle.