One is handy with 45HP if you have a 999cc Panda and just love to go around roundabouts fast or take it on trackdays. It is not the power that creates the requirement, it is the usage of the vehicle. The more power you have, the more you might notice it not going down through corners in comparison to straights. Turbo cars can benefit more in general due to an increased reliance on traction due to their high torque output. Suspension and tyres are the first port of call for these sort of traction problems though.
FIAT/Abarth obviously don't think it's needed up to 200BHP with the driving expectations of their customers.
I'd love one in my 500 but I think it would be rather wasted in a 1.2. Still surprises me that a 1.2 with 69bhp and grippy 195 width tyres can spin its tyres so easily.