The Malthusian principle of population growth was only based on observations and statistical extrapolation of demographic and census data from Western Europe at the end of the 18th century, during the height of European imperialism. Malthus was writing about a universal theory, based upon research and evidence from only one segment of the globally elite Western European population during that time period. There is a significant temporal and spatial difference between the technology available, efficiency of food production systems and global population from 1798 until the present day. What about new developments and technologies in vertical farming or drip irrigation that reduces the amount of space and resources needed to produce more quantities of food.
There is a sense of environmental determinism, racism and Eugenics in attempting to reduce the diversity and complexity of the human population into a singular mathematical equation. Malthus did not consider or discuss any sense of agency from the people of colonised countries or the "New World" - The Haitian revolution led by former self-liberated slaves occurred around the same time and they were able to self organise food production and birth rate. Malthusian theory placed emphasis on controls to limit population growth including forced sterilisation and disallowing certain "undesirable" people to reproduce (Eugenics). A lot of Victorian era polymath's theories were rooted about experience and data gathered only from imperial countries and societies - except for evolution and Charles Darwin / Albert Russel Wallace who travelled across the world to Indonesia and the Galapagos Islands.