I get the joke, but in ideal world, in microservices, there is no such thing as code duplication across services. As a maintainer of a service, I should not give a crap about code present in some other service - it's some other team's code, why would I care? I don't have to even know that the other team exists. In big systems, it happens that I can't even feasibly know the existence of all the applications.
I don't. Other teams - maybe they do, maybe they don't. Who cares, not me. I have responsibility for services of my team, I think we are doing a good job.
Being selfish is the core principle of microservice architecture.
Except 9/10 times microservices end up wildly dependent on each other, yielding a distributed monolith. Better to use service oriented architecture and just ship the monolith, you can test easier and skip the extra layers of serialization / deserialization.