Earlier quoted context omitted.
It gives you a consistent design system with sensible defaults and easy-to-use (and rather memorable or easy to deduce) utility classes. Unlike the yet-another umpteenth bespoke `.card-header__buttons .card-header__button--secondary` that no one can remember and create an umpteenth+1 Tailwind works great when your site/app is a collection of components
`.card-header__buttons` that example makes no sense unless you use global CSS/SASS, which very few projects do anymore. Component CSS/SCSS or CSS-in-JS are very common which resolve this scoping problem. So why bother with a DSL like Tailwind over Component CSS/SCSS for example?
Everywhere I've seen CSS-in-JS used, everywhere it's people busy writing bespoke styles in every file.