Well, I still use some UML diagrams fairly often. Not so much for permanent or comprehensive system documentation, but to help me think through specific features or behaviors, and communicate these designs to others. I usually use a smallish subset of UML, because this usage doesn't require deep details.
I did give up on WYSIWYG tools for this, though. PlantUML support in VSCode is pretty good.
I did give up on WYSIWYG tools for this, though. PlantUML support in VSCode is pretty good.