A JS framework called Torpor: https://torpor.dev (https://github.com/andrewjk/torpor)
Been working on this for a while, with the aim of making something simple and immediately usable. Components are JS functions, containing UI that is (mostly) HTML, with reactivity only done through proxied objects.
To test it out I built a distributed social media/microblog site called Redraft: https://redraft.social (https://github.com/andrewjk/redraft)
Self-hostable or hosted for a fee, all your posts stored in an SQLite file, comment/like/react on other people's Redraft posts via a Web extension (pending approval, but you can use the unpacked version from source).
Both are in a pretty rough state, but usable for the intrepid.