With multiple repos, we can get a single deliverable for each project requirement, manage convergence and still maintain a main branch for each repo. The artifacts can be packaged and consumed by the other dependencies that are changing. It stops monolithic development. It library A needs to branches of change, we don’t need to create 2 branches for the entire product line. You literally only change the parts you are currently working on, and insignificant changes don’t get sucked in by proxy.