Isn't it much easier to know you're going to use React (or Svelte or Vue or anything else) and just start there? Starting a build in HTML-first only to bolt on a JS framework after the fact seems like a lot of wasted effort.
I'm not sure what that looks like, because if it gets complex enough it's a sign I need to refactor, imo.
It worked, it was a lot of fun to write because it went really fast, even with some bells and whistles. Whole thing was my escape hatch when datalist attribute didn't work. It also worked well.
Alpine JS feels like a simpler version of Vue 2 without a build step and without any of the complex or confusing stuff (and of course with a focus on HTML not rendered by JS).
But when I saw what this turned into as a BE colleague copied it to the next form, making some adjustments... oh my, I prefer external and reusable JS (or a JS-first approach to templating, like React) any day.
Still, Alpine is really awesome for minimal interactions and simple JS.
When working outside React, it's hard not to miss it for the simplicity of doing everyday stuff inline in the HTML.
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.
Copying still happened, take that as you will - in this case that was the problem :) Might be my implementation was not generic enough, but tbh the colleague was not especially proficient at JS. We had a productive conversation about this, but this particular project ultimately was lost by my former employer. The reason was not this autocomplete component though :)