True, but the article is about projects getting de-platformed, so all that goes away under those circumstances. There’s value tied up in all that data, but the codebase itself might be far harder to replace securely if the public repo just vanishes. Better to have at least an alternate offsite backup - on another service even - if all you do is maintain a project-owner-controlled clone.

Plus, I know it’s a small gesture, but some folks might need that tiny push to migrate if they’re already fence-sitting about leaving.