Conversely, poorly-structured microservices are just monoliths where most of the code is in other repositories.

I guess that the benefit of monoliths in the context is that they (often) live in distinct repositories, which makes it easier for Claude to ingest them entirely, or at least not get lost into looking at the wrong directory.

One problem is that the idea of being "well-structured" has gone overboard at some point over the past 20 years in many companies. As a result, many companies now operate highly convoluted monolithic systems that are extremely difficult to replace.

In contrast, a poorly designed microservice can be replaced much more easily. You can identify the worst-performing and most problematic microservices and replace them selectively.