Yes you're absolutely right that these language dialects keep emerging because regular languages don't have quite the right features for reactive computations.

Yes you're absolutely right that these language dialects keep emerging because regular languages don't have quite the right features for reactive computations. Still, OOP was originally designed for GUIs and is a great fit for that, it's easier to build functional stuff on top than the other way around (apparently, judging from experience of having used both). The closest I found to what I mean is that JavaFX has a whole observables framework, and there's ReactFX that builds a lot of stuff on top of it. With a small change that I prototyped in the past you can do what React Compiler is trying to do, where you run code and record what properties are read then register dependencies and re-run on change. It's quite a natural fit.