How would there be more people?
The death rate is higher than the birth rate and has been since the dawn of man.
Untill recently, in terms of the earths lifespan, people were dying of things as simple as colds, flu and diorrhea. People in undeveloped countries
are still dying of these things but before the last century there was no cure at all.
The plague, two world wars and countless other global events have wiped millions of people out.
The first generations of humans were vulnerable to wild animals due to lack of weapons.
Untill recently a great number of people were dying of diseases that are now curable.
now that these problems have been solved there mayl be a population growth, as you said there should have been, but this will however present more
problems such as overcrowding; providing food and water for more and more people, as well as fuel and accomodation; and the spread of more diseases as
more and more people gain access to global transportation.
Transportation not just of humans but also of fruit, vegetables, meat, plants and livestock, all of which could carry life-threatening diseases.
Immigration and importation introduces lifeforms to an unfamiliar enviroment, not only reintroducing diseases that have already been irradicated, but
also exposing the newly introduced lifeforms to diseases common to the new enviroment that they may not have encountered, so have no immunity
In otherwords, what I am saying is that disease and war are a constant threat to humans, as well as other lifeforms, and will always deplete the