The problem of population is not the total population. At least not yet.
It is the structure of population.
You can have 1.5B people like India and China..but if every family has 1-2 kids then you'll be fine.
For really economy start at family level.
I don't think it's a big deal for many to raise 1 or 2 kids - however poor they are - especially if they are 2 parents or like China 4 parents if you include the grand parents. 2 or 4 adults can easily feed/educate 2 kids. Just like not big deal for adult to feed themselves if they are single.
The problem in Africa is having too many children per person.
Africa is not populated.
The world is not populated.
Cities can carry incredible amount of people thanks to building technologies.
New York has 10m people living in the area the size of Nairobi City.
So the world carrying capacity is huge.
We can squeeze 50M Kenyans in 3 mega cities of 15m each.
Africa just need to reduce the number of kids per family or woman.
And poverty will become history.
I remember reading this article by some Kyuk academic that made me doubt the over-population thing, particularly as directed towards Africa. Dude cited stats that made me think if its a prob, then it's a developed-world problem, not an African problem. Not only are they densely populated, as you state, waaaaay more than us, they also use up resources to a crazy tune: something like, one American uses up 35 times the amount of resources as one Indian and 53 times as much as a Chinese or something like that: Now imagine the comparison to Africa? Would not surprise me if one Amrican uses as much as 100 of us, I swear.
Also, the UN's food body, FAO, calculates that we already produce food sufficient for 12 billion healthy people today! Yet world population estimates for the turn of the century, year 2100, is 10 billion only. So, we literally are producing more than we need: We just don't distribute it to everyone who needs it. So about 2 billion people are too poor to buy it, but it's available. In terms of the other resources, the problem is squarely in the West! They need to reduce their population to like 20% before their "concerns" about our overpopulation can begin to sound like something other than blatant racism to me.