That seems a little strong. We're talking about a potentially complicated system in a technical field. Some standardised notation and terminology could be helpful to keep the visuals concise and unambiguous. I agree that this looks far too complicated, though.
So I think it’s not a worthwhile investment. The non-techs can’t create or edit and typically can’t read. The techs don’t use it for what they are creating.
I’d rather spend time on docs in the actual system components or teaching non-techs enough to read autogenerated docs or walk through code that actually is the system. Then couple that with block diagrams written on whiteboards or powerpoints or whatever. If you get to the point you need notations it’s too complicated and point them to the appropriate source.
This isn’t easy. But I think it’s easier than pretending that both sides learning an artificial middle language (uml, etc).
Because construction analogies are stereotypical if you are building a building. A big, expensive skyscraper. If your construction workers speak English and your financiers and architects speak French. I think you’re better off investing in hiring some people who speak both languages than in making them both speak German to work on blueprints.
I have often seen a group of developers discussing something and then someone sketches a simple diagram showing entities and relationships, transitions of a finite state machine, or message-passing similar to what UML would call a sequence or communication diagram.
However, in my entire career, I have never seen anyone actually draw out fully annotated UML diagrams using the official notation, nor any instance of some of the numerous diagram types UML specifies. And that includes working at places where everyone had been given UML training!