I’ve seen Alpine, and it is interesting, but another bullet point in my wish list is vanilla JS; no new template language. JSX is just a small bit of sugar on top of vanilla JS, in my mind, so it is acceptable.
From the brief glance I've taken at Alpine I didn't think it did have a template language - unless you refer to it's use of custom html attributes?
Alpine has directives like x-if and x-for. For a lightweight templating library I would recommend https://pure-js.com. It's been around for ages. The PureJS directives take some time to get used to, but are quite powerful once you do.