It keeps the HTML about as clean as it can be, more often than not. Many of these classless CSS frameworks you can substitute arbitrarily without ever changing

It keeps the HTML about as clean as it can be, more often than not. Many of these classless CSS frameworks you can substitute arbitrarily without ever changing the markup. Which can be very useful for small static sites with hand-edited HTML like the Old Web people used to bake. I certainly appreciate that "Old Web" feeling from the time before CSS when Browser default/built-in stylesheets were more opinionated and tried to do nice things without forcing you to do all of your styling by hand. Classless frameworks can feel like a good throwback to that era, and a useful compromise from today's browsers' awful default styles and the sorts of CSS frameworks that include everything and a kitchen sink and are designed much more for "apps" than just a clean document full of information.