Tailwind * tries * to resolve this, but is probably just a different bird's nest.
There are numerous React frameworks that supply a "widget set" either of web page elements, UI controls or both that work out of the box.
If you (your client, your employer, ...) like the way these look out of the box they are a great way to build something quickly and not have to understand the underlying CSS.
If you are required to customize the look, however, or you want to combine components from various sources and have them look consistent you have to understand all the concepts of the frameworks, the frameworks the frameworks depend on and CSS.
Ideally as you write more code you get more reuse and writing future code becomes faster. In theory CSS classes act like this too. As you have more (well designed) CSS classes then writing future CSS becomes easier because you can reuse the past work.
Tailwind breaks this benefit that by encouraging you to write your CSS with glorified styles.
And code that uses Tailwind is reusable as long as you use components (React, Vue, Svelte, WebComponents, CSS components with @apply, it doesn't matter). Those are reusable.
Trying to use Tailwind without components, in a CSS-garden style page for example, is just trying to fit a square peg in a round hole. It's just the wrong tool for it.