LiveView is, unfortunately, somewhat of a footgun. The idea is super neat and works great on localhost -- but then somebody clicks a dropdown with a dynamically rendered list of whatever in production and has to wait half a second for a piece of UI to appear, and that's really bad.
The Nitrogen Framework for Erlang [0] is another in a similar vein (and pre-dates LiveViews).
Another is lamdera [1] which I came across on the Elm Radio podcast [2]. I've never used it, but the focus on minimising accidental complexity between front and back end was appealing, (along with the use of Elm).
A few other backend frameworks for other languages also have something like that.