I don't know for React/Angular, but with VueJS you have:

  <style scoped>
  .a-class-that-will-not-leak { /* ... */ }
  </style>

Considering this feature, what's the difference between writing CSS properties or using Tailwind's @apply ?

Also, such CSS classes are also available in frameworks like Bootstrap or Bulma:

  <a class="has-text-weight-bold has-text-centered">

But they also give me:

  <nav class="navbar"> ... </nav>

Which would be responsive and functional, unlike the one I would implement with homemade CSS.