I'm the developer of depshub.com (for automated dependency updates using AI) and even though a single metric isn't valuable, having any sort of indicators and metrics is very useful when you have more than one repository. Being able to quickly see if your repositories are getting better or worse over time helps to understand when the dependency updates should be prioritized (if so) in the first place. There are a few core metrics that I've built (major vs minor vs patch ratio, security updates, etc.) into the product, and it's one of the most used features up to date.