I understand that CSS style sheets are cached in browser. My question is, why? CSS is usually only kilobytes, so what is the benefit of caching something that small when it can prove so bothersome to update? My only guess is that browsers like CSS to be loaded before HTML so unstyled elements are not flashed.
Every CSS file is a HTTP request. Many requests means slower page loading. Browsers developers cannot be sure that the websites developers will create one minimized CSS file with less useless lines. Often websites contains dozens of css files, sometimes there are not kilobytes but megabytes. So the CSS caching part is really in service of websites developers.