Alpine is primarily designed to be reused via server templating. You use a single template per component to do the in-HTML side, using the server template's facilities to handle variations as necessary. Then you can factor out complex common behaviors into Javascript using Alpine.data.

It definitely does have a maximum size of project it's suitable for. In particular, it's thoroughly individual-component-based; changing anything outside the component requires tacking on non-native hacks, and doing a full interactive app with it would be a painful exercise. But for adding simple interactivity to a primarily server-rendered web page, I've found it to be quite useful.