Whether or not you obsess over the particulars of overpopulation, Malthus’s theory is more broadly one of human pressures on the environment, and the lack of suitable equilibrating mechanisms at anything other than extremely high human costs.
The simplest version of Malthus is an account of how the world runs when all essential factors do not grow at the same rate, and in particular those growth rates diverge in a roughly consistent and sustained manner. At some point one of those factors becomes too scarce and the system crashes, leading to a plunge in living standards and possibly a population crash as well. In this sense Malthus is presenting a general rather than a special case, as it would seem that roughly equal rates of growth for the essential factors is the unusual setting, not the default setting.
For Malthus it could be said that the idea of equilibrium triumphs over that of progress.
It is also striking that Malthus was a major influence upon both Charles Darwin and Alfred Russel Wallace and their path breaking theories of evolution varying, and groups of people popping in and out of existence, helped them both formulate their theories of natural selection. Malthus thus helped to drive the very existence of modern evolutionary biology.