What broke your database diagram workflow in real projects

At the start of most projects, database diagrams feel really helpful.
Everyone understands the structure, relationships are clear, and discussions are easier.

Then the project grows… and somehow the diagram gets left behind.

I’d love to hear what actually broke the database diagram workflow in projects you’ve worked on.

• Was it too many migrations happening too fast?

• People changing the schema directly in SQL?

• The diagram slowly drifting away from production?

• Tools becoming annoying to keep in sync?

• Or simply no one feeling responsible for maintaining it anymore?

When did diagrams stop being useful for you — and what was the real reason?
I’m especially interested in concrete stories from real systems, not ideal-world answers.