Let‘s say we start with 2 humans.
They have 4 children. And so on. Meaning the population doubles every generation (~30 years)
How many years until you reach 8 billion?
The answer is 990 years.
Have Anons ever heard of last thursdayism? Dinosaurs? Lizard people?
Now you might say
„But Anon! Humans Die!“
And you would be correct.
It is said that the 8B humans today are around
8-10% of the humans ever lived. So we need to grow our population numbers by a factor of 10 so we reach approx. 80B humans.
This would happen after less than 4
Additional generations.
Meaning it would take all of 1110 years to go from 2 humans to 80 billion humans if we assume each couple has 4 kids.
With some death, famine, and rounding the required number of years would probably grow larger.
But still, it seems much closer to the biblical 4000 years of humanity than the purpoted 300k+