In Defense of Utility-First #CSS | frontstuff
From a file size standpoint, you shouldn’t worry about repeated class names in the HTML. That’s what Gzip is for. The deflate algorithm was specifically made to handle duplicate strings, so there’s no point in trimming away characters in your HTML. The resulting file size will make little to no difference whether you use a few or a lot of classes.
On the other hand, the more a selector is repeated in a stylesheet, the more work your browser has to do to resolve all styles.
HTML “bloat” doesn’t matter, but CSS does. The network and engine don’t care how many classes you have in your HTML, but the way you write your CSS counts.