The problem I mostly see is that each of this body of knowledge has their modelling tool, one where you need to have some form of workshop or certification (UML, Archimate, BPM etc etc..). What EventStorming tries to do is minimise these handover from proxy domain expert to avoid cognitive bias made from telephone games. So it tries in a simple and quick way to share knowledge in a multidisciplinary group and create a shared mental model, and do this continuous. It tries to show ambiguity in the language (something DDD looks for to create bounded contexts).
About the facilitation, you are totally right. A good facilitator is what makes or breaks it. Besides EventStorming is not a silver bullet, it has its flaws and its blind spots. So then you need your facilitator to grab out their toolbox and see how to battle this