Had no real benefits, was way more cumbersome for almost everyone and honestly even me as a developer I'd rather have a few paragraphs instead of a diagram.
Somehow it's just never "readable"
I find that tools like Mermaid are pretty invaluable, especially when editing very large processes. Draw.io diagrams tend to get pretty unwieldy as they scale and editing inter process stuff if you forgot something quite frustrating.
Sequence diagrams are possibly my favorite feature in Mermaid: https://jessems.com/posts/2023-07-22-the-unreasonable-effect...
Admittedly I primarily use D2 nowadays. The only features I miss in D2 from mermaid are the GitHub automatic rendering and Sequence diagram numbers. https://play.d2lang.com
When I've used dot or mermaid to build diagrams I've always found it hard to specify layout, colours and sizes, which I use to emphasise different views on a system. I'd love some sort of middle ground where I get the benefits of version control but also the sketch-like character of excalidraw
For the complex one, maybe yes, it makes sense to have an overview and I think maintaining that vs text is also easier. However from what I've seen, most things can be boiled down to a list of 1, 2, 2.1, etc.
My colleagues frequently use one of these general-purpose WYSIWYG drawing tools, and I'm not a fan at all – everybody has their own slightly or wildly varying riff on UML or flowcharts, and the result is chaos: Sometimes rectangles are states, sometimes they're decisions; sometimes arrows are labeled state transitions, but other times they're unlabeled and state transitions are also boxes.
Discoverability is also much worse compared to e.g. Mermaid or PlantUML diagrams checked into version control or stored as text source in Wiki articles.