This is just a casual observation from a back end/infrastructure guy perspective.
Does building a rich GUI experience on a web application need to be this complicated?
I still remember the days when rendering are mostly done on server side and Javascript was used as progressive enhancements. The web application back then were quite interactive and building them were somewhat simpler than the current state of the art.
A tiny dom lib like https://github.com/WebReflection/uhtml is more than enough for very complicated UI, with understanding how events work, will be able to implement very thin state management on top. With game programming styled manual render() call here and there as needed, pretty neat.