If you have many services composing your platform it is easy to get lost. This is especially true for the a microservice environment. While you might want a great independence of the teams (which do have everything they need under their control) reusing services sometimes is advisable. This might be services like authentication or a central user service.
A growing number of service means also a challenge not only for developers. Which service runs where? What does it do? Who is responsible for that?