I don't get why people would use something like this, for most use cases this seems like a massive step back. I guess it's for applications where you want a lit

I don't get why people would use something like this, for most use cases this seems like a massive step back. I guess it's for applications where you want a little bit of interactivity but not build a complete single-page app. Which seems like a pretty small niche. The amount of boilerplate code and mental modeling needed for such a simple example seems absurd though. Personally I would just embed a small single-page app/snippet instead where I need more interactivity, stitching together server-rendered HTML like this seems quite bad. React for example is such a small and easy to use library, you don't even need a compiler toolchain to use it (makes code nicer to read of course), just drop the JS bundle in your HTML and write your component in a script tag, it will still be much easier to understand, use and modify than this.