> Taking said dependency does not turn a microservice into a monoloth.

True. However one of the core tenets of microservices is that they should be independently deployable[1][2].

If taking on such a shared dependency does not interfere with them being independently deployable then all is good and you still have a set of microservices.

However if that shared dependency couples the services so that if one needs a new version of the shared dependency then all do, well you suddenly those services are no longer microservices but a distributed monolith.

[1]: https://martinfowler.com/microservices/

[2]: https://www.oreilly.com/content/a-quick-and-simple-definitio...