I have not used Dependabot myself, but I wrote a tool that runs in a nightly CI job and creates or updates a single PR per repo with all of the dependency updates. You can then merge those with the push of a button. I think that's better than the more granular approach of having one PR per update.

This still lets me know when an update to ANY internal or external dependency will break the build, so that I can take a look.

My tool only works with Nix Flakes, so it updates dependencies of Nix packages, but you often have other language-specific package managment tools wrapped inside of Nix (e.g. nix calling cargo) and I think it would be a cool extension to add a configuarable language-specific shell command where the results of running that command are added to that single PR as well. That could document the exact update workflow a dev should go through while also regularly exercising it.

https://github.com/serokell/update-daemon is a better tool than mine that does the same thing and I have been thinking about adding the feature there. I'd be interested in discussing that idea further, maybe I'll open an issue for that.