The article is primarily talking about keeping your CSS modular... writing CSS that applies only to one "component" of a page (e.g. a box in the sidebar or a header logo or a navigation menu or whatever).
LESS and SASS have more to do with the fine-grained details of CSS syntax... primarily reducing repetition (via nesting, mixins, variables, etc).
I personally wouldn't worry about any one particular technology (other than CSS itself), but I have found over the years that the most immensely helpful technique when working with CSS is keeping things as modular as possible. Basically, ignore the "C" (Cascade) in CSS, either with compiled / scoped components (like the linked article is talking about) or through a naming convention like BEM or SMACSS.
LESS and SASS have more to do with the fine-grained details of CSS syntax... primarily reducing repetition (via nesting, mixins, variables, etc).
I personally wouldn't worry about any one particular technology (other than CSS itself), but I have found over the years that the most immensely helpful technique when working with CSS is keeping things as modular as possible. Basically, ignore the "C" (Cascade) in CSS, either with compiled / scoped components (like the linked article is talking about) or through a naming convention like BEM or SMACSS.