Teams meet, discuss, and decide to have a microservices strategy.
They start migrating the monolithic system to microservices, along the way they decide to build new features, for the sake of speed, those new features have to be built inside the monolithic system, and later be migrated to microservice.
A divide happens in teams, with half migrating to microservice and half adding more to the monolithic system. At one point, the team migrating to microservice is rushed to support more features into the microservices they just built without consideration of the bigger picture, after huge number of resources spent, they are back to square one, with a legacy monolithic system, and half cooked microservices that kept growing until they became other monolithic systems.
Then teams meet, discuss, and decide to have a microservices strategy.