CSS Utility classes are "faster" and that is the draw, but once they have been overused and abused, then you are either stuck with them, or you spend a lot of time cleaning the tech debt and rewriting the css properly.
At my current job, I work on a legacy application which is still actively developed and released. I spend a lot of my time cleaning up inline styles, styles that are applied via javascript calls, and style blocks on individual pages. I wish the inline styles would have been utility classes, because at least then they would be easy to find and replace, instead, there are "margin-top: 3px" and "margin: 4px 0 0" and "padding-top: 2px" and dozens of variations on that that had they just done something like ".mt-small { margin-top: 3px }" there wouldn't be so many variations and inconsistent looking pages. This company would have benefited greatly from Bootstrap or Tailwinds. I hate both of those, but there is no denying how easy they are to use and abuse.
At my current job, I work on a legacy application which is still actively developed and released. I spend a lot of my time cleaning up inline styles, styles that are applied via javascript calls, and style blocks on individual pages. I wish the inline styles would have been utility classes, because at least then they would be easy to find and replace, instead, there are "margin-top: 3px" and "margin: 4px 0 0" and "padding-top: 2px" and dozens of variations on that that had they just done something like ".mt-small { margin-top: 3px }" there wouldn't be so many variations and inconsistent looking pages. This company would have benefited greatly from Bootstrap or Tailwinds. I hate both of those, but there is no denying how easy they are to use and abuse.