I think rather the issue being new library popping up is more about choosing the right tool for the right project.

If you know that your project is going to be small-scaled (a MVP or POC, a blog, a UI for your home lab, a static website, etc.) then mizu and tools alike may be a good choice.

If you know that you eventually want to have thousands of customers, with hundreds of collaborators, then it might indeed be not the best fit. Going with a more "common" framework like the big name React and Vue is probably better.

Web dev nowadays offer a wide range of application, so everyone needs is different so a one-size-fits-all framework/library is almost impossible to achieve in my opinion