The world passed 8 billion people a few years ago in November 2022. It took all of human history until 1804 to reach the first billion.
Look at the right column, The gap between milestones shrank for over a century and then stopped shrinking. That flattening is the the main aspect of this presentation.
Source: UN Department of Economic and Social Affairs, World Population Prospects
Each bar is how many years it took to add one more billion to the population. From 1927 to 1974 the wait shrunk from 33 years to 14.
After that it barely moved much. Humans still adding a billion roughly every 12 years, but the rapid acceleration of population growth is gone, and the next billion is expected to take much longer.
In the mid 1960s the average woman worldwide had about 5 children. Today it's about 2.3, hovering close to the replacement level of roughly 2.1.
Population keeps rising for a while after fertility drops, because there are still many younger people having kids. But the process is slowing.
Approximate global fertility, UN World Population Prospects
~10.3B
The UN's 2024 projection has world population peaking out around 10.3 billion in the mid 2080s, then slowly declining from there.
Some countries are actually shrinking rigth now. Japan's population has been falling since the late 2000s. China's started falling in 2022.
UN World Population Prospects 2024, medium scenario. Projections, not certainties.