Can't relate. Tailwind works fine with anything that supports PostCSS. I run it with Vite and there's zero issues.
> the state management ecosystem is fractured between vuex and pinia
This is also just not true. Pinia is officially replacing Vuex as the recommended store library for Vue [1]. They're also vastly similar in how they do things, so the knowledge transfer over from Vuex to Pinia. And Pinia just address most of the design goals mentioned in the article in the most simple way.
As for Vue 2 -> 3 transition, lots of the larger UI frameworks in the ecosystem is struggling to migrate, despite lots of efforts on the compat layer to smooth the transition, which is a bummer. But as long as you're not doing those sophisticated things, Vue 2 examples should work out-of-box on Vue 3 as well. There are surely less resources for the composition API, but the official introduction guide has been good enough in my experience.