I'm not sure OP was necessarily implying that the Pi specifically wasn't suitable for the job -- perhaps just that requiring /any/ other additional computer to achieve this is not without additional administrative overhead and power costs.

It does seems likely that a Pi is going to consume a fair bit less energy than the x86 SFF PC, so it's probably a net gain there, but that admin overhead thing isn't necessarily one to ignore -- it's not entirely set and forget.