I wish this existed when I started my project 5 years ago. I had to design a database schema for a full stack project using postgres. I was working with a scientific domain expert, and it was very helpful to have a diagram to review, so they could identify issues that might arise due to future domain specific needs.

This caused many one-on-one meetings where we would look at the diagram, and I'd note changes to be made for next meeting.

With this, we could have made changes live during meetings, and saved many iterations.

Things like pgadmin existed, but it didn't look as friendly for non-technical folks. This might decrease some friction.