For the second group, I don't think it is about inventing things anew.. most of the time, it's just an efficient way to get things done.
A lot of time the centralized ops team is very slow or just not very good. Your tickets may take weeks to be processed, or critical requirements are ignored, or maybe central ops team only cares about closing tickets and does minimal possible work to satisfy the letter of the requirement.
If there is no one on your team who can do better.. well you suffer and work with central team. But if your team has someone who can do this and the autonomy to proceed, then your can work much faster -- no need to wait weeks for to allow the other team to access your data, you can grant the permission yourself in under a day.
A lot of time the centralized ops team is very slow or just not very good. Your tickets may take weeks to be processed, or critical requirements are ignored, or maybe central ops team only cares about closing tickets and does minimal possible work to satisfy the letter of the requirement.
If there is no one on your team who can do better.. well you suffer and work with central team. But if your team has someone who can do this and the autonomy to proceed, then your can work much faster -- no need to wait weeks for to allow the other team to access your data, you can grant the permission yourself in under a day.