Why not serious in this case? A full-featured browser makes is the most important thing to make an OS usable today, isn't it? Of course I assume all the basic stuff like file system and device drivers, relevant multimedia codecs, bash or a likely-featured shell, SSH, basic GNU/BSD/alike command-line tools are already there. And that things like LibreOffice, ImageMagick, LaTeX, GnuPlot, Inkscape, VLC, runtimes like CPython and OpenJDK are next in the queue. But what is the most important thing which makes an OS usable today? For me it seems obvious it's the browser. If only there was a browser supporting all the today standards (including the H264 and AAC codecs support) I would already be able to do everything I need in it, the rest mentioned (after "And that things like") would just make my life slightly more convenient and fun.