A321pf vs 757pf

why is the s321frieghter have less than half the capacity of the 757 pf when they are similiarsize aircraft

Haven’t looked into any details beyond MTOW, but that is more than 20t higher for the 757 compared to the A321.

I investigated it the higher Mtow in due to weight of the fuel and aircraft itself the cargo capacity showed 27 ton for the A321 vs 28 tons for the 757