Why not both? I've been using https://github.com/mateodelnorte/meta and having a great time so far, it's just that GitHub (and others) don't have a simple way to bundle multi-repo commits in pull requests.
I agree with Christian... Why not both? Lots of teams I interact with have great reasons for a monorepo which they admit requires some work in tooling and processes and claim they're successfully releasing software faster with less effort if their code lived in disparate repos. I believe teams must choose the appropriate patterns that work best for their architectures and situations.