Agree with this and I think it's the crucial point. Where I've had the most success with UML-like tools and diagrams is early on in a project since its much faster to rip up and rebuild a few diagrams. The diagrams also help with getting consensus among stakeholders that this direction makes sense and doesn't have any glaring holes.

Later on you can drop the diagrams entirely and perhaps keep them as some onboarding documentation if they're still useful.