I'm inclined to interpret monorepos as an anti-pattern intended to mask away fundamental problems in the way an organization structures it's releases and dependency management.

It all boils down to being an artificial versioning constraint at the expense of autonomy and developer experience.

Huge multinationals don't have a problem in organizing all their projects as independent (and sometimes multiple) source code repositories per project. What's wrong with these small one-bus software shops that fail to do that when they operate at a scale that's orders of magnitude smaller?