Sometimes we built for the pure joy of making. Practicality is a bonus.
You've built something really great here, your grasp of web components is incredibly strong, and the way you use TypeScript is very light handed in a way that made the code just a delight to read through, in a way I've not had in many years. It's been a while since I looked at a new library's codebase and learned something new, so thank you for that!
This may sound silly, but I think you've laid the foundation here for the next Bootstrap / MUI. It just needs more expandability and distribution options.