Take the case of the power law applied to the city.
According to a power law, Can a city infinitely grow?
I don't think so.
No, the power law doesn't tell you a city can infinitely grow.
Also, Giovanni says he wouldn't take his own model valid after a couple of orders of magnitude growth.
The model says that the growth of animals, cities, and other living creatures observed so far, follows such a scheme.
Of course, if we don't see animals that are 10x bigger than the blue whale, probably other factors impact the growth of such an animal. Of cours,e the model is not complete.