Several people have pointed out the redundancy, even hypocrisy, with `@apply` and compositional classes. I like to think of `@apply` and componentization as competing solutions. Just like "composition over inheritance" I believe in "componentization over @apply / composite classes".

Ideally, you don't have composite `.btn` classes. You simply have a `<btn>` component which encapsulates appropriate Tailwind CSS classes in the component (no external CSS, `@apply` required).

With this framing, `@apply` is the less preferred of 2 approaches. It's good, even necessary, in some situations, but generally you should seek ways to componentize vs. abstracting compositional classes.