This is in part due to the awesomeness of NPM. NPM seems to be a default for many developers looking to solve problems with a library and not considering the extra payload it will add to their applications. NPM packages are primarily for NodeJS and although many do provide browser bundles, often these are transpiled using polyfills and other unnecessary code to make them compatible with all browsers.
Being able to style components and enhance them in a progressive way can all be done natively with CSS. Using modern features like CSS variables and taking the time to split CSS into per page (or route) styles can lead to good web application performance.
The governing body for professional cycling in Great Britain, hired Dave Brailsford in 2003 as its new performance director. At the time, professional cyclists in Great Britain had endured nearly one hundred years of mediocrity. Since 1908, British riders had won just a single gold medal at the Olympic Games, and they had fared even worse in cycling’s biggest race, the Tour de France. In 110 years, no British cyclist had ever won the event.
Brailsford had been hired to put British Cycling on a new trajectory. What made him different from previous coaches was his relentless commitment to a strategy that he referred to as "the aggregation of marginal gains" which was the philosophy of searching for a tiny margin of improvement in everything you do.
Just imagine how better the user experience will be.