Yes and no: Maybe the rest of your workloads don't require much CPU- you only need this kind of power for one or two workloads, and you don't want them getting crowded out by other work potentially.
Or they require a GPU.
Or your core service only needs 1-2 servers, but you need to scale up to dozens/hundreds/thousands on demand, for work that only happens maybe once a day.
Or they require a GPU.
Or your core service only needs 1-2 servers, but you need to scale up to dozens/hundreds/thousands on demand, for work that only happens maybe once a day.