> "I frequently imagine something that takes the best ideas from react/redux and from other ui and layout frameworks and lets you build something that has consistent, cross platform (desktop and mobile, maybe even web with some kind of compilation pathway to js or webasm), responsive ui, without the huge web stack."

There are a number of existing UI frameworks that fit this description. As a starting point, I'd suggest checking out QML:

https://en.wikipedia.org/wiki/QML