If both are the same, then you are carrying additional dead weight
Just kidding there, normally when the cc is more with the same performance figures is because they have to get the certification by the homologation authorities (ex. ARAI in India) to meet the tailpipe emissions under control. Usually, mostly power to capacity ratios are due to this, and most others are detuned for lower power to meet the national standards for road safety regulations, and also practicality of the end user is taken in account too. We Indians are very curious in the quantity rather than quality in general, so the psychological factor is also there
The de-tuning is also done to achieve savings in the costs in complete development/redesign a lower sized engine/powertrain which eventually add to the costs finally to the car/automobile owners.