Overkill, yes but also almost surely just a standardized hardware set the company uses regardless of the specific advertising situation.
This set of hardware can run 99% of their client requirements and requires only a single hardware configuration to support. Maybe a couple generations of support as time goes on before older hardware is replaced.
Could this particular use case be handled by something as simple as a raspberry pi? Probably, but almost surely not everything the company that provides the hardware/service/support handles for clients.