[noypiscripter]

I don't think so. You could fully customize using css_additional and you don't have to use stylevars if you wish. But IMO, there are some things that are easier to do in the stylevar editor than in the css_additional. And besides, the stylevar editor is useful for basic customizations and it doesn't require someone to know CSS. For advanced CSS users, to fully customize the site would require mostly using css_additional but for the basic stuff like font, link color, hover color, wrapper width, body background, etc would be best and easily done using stylevar editor. And most importantly using stylevars would lessen the size of css_additional which means the css would load faster.