I used Tailwind v1 to build a WP theme years ago. It was still useful to enforce the design system and color tokens. With the Block Editor, I imagine that's even more true now. The hardest part is customizing all of the different modules/plugins to either use TW classes (via injection somewhere) or write a custom CSS file with `@apply` rules.

The WP theme templating system has partial file includes, so creating "components" is certainly possible.