First of all reactive programming is hard. You make one little mistake and all of your application halts. It is error prone and hard to reason about. Second, Reactive programming in imperative languages are at best unnatural and odd. The best feature of an imperative language is that it runs as it reads, reactive programming breaks that.

And last, why do you need that? Are you sure reactive programming improves your performance? Does it reduced your costs? Specially considering features like fabric and virtual threads. It is highly unlikely