I'm not sure I agree much at all, but I take issue with your last statement. Why on earth would I ever want to move to anything remotely like ReactJS when I'm building a single user application? You must carry state information, and in that case explicitly having state is both often conceptually simpler, easier to modify/debug, and require far less code than using something literally insane like using js + DOM.
It's good to have varying opinions. I'm unsure what you're considering positive about state. Synchronizing state among multiple widgets in QT for example is a pain and quickly becomes become fragile. To help deal with this, QT 5 introduced a JavaScript based reactive programming framework before ReactJS was popular. See https://en.m.wikipedia.org/wiki/QML#Property_bindings Perhaps not completely an insane idea to some :)
