* Nature has been trying to fix sub Saharan Africa for the better part of 100 years but white people keep interfering.
* The US and EU do not really have any border control at all to the extent people are willing to live in an underground economy. There is NOTHING stopping people from just showing up here, make a fraudulent asylum claim, then being released into the wild with a court date to come back to.
Now if they do not show up, they will be ordered deported. This is meaningless however if you just use a fake name when you enter, or live by a fake name later.
Alternatively, you can play ball with the asylum process and enjoy free housing, medical care, and government checks during the typically more than five year process that it takes to reject an application, appeal the rejection, and appeal the order of deportation. After that you can disappear to evade the deportation order, or use the 5+ years to have an anchor baby or marry a US citizen.
There is no limit to the number of people who can do this in the US or Europe. At current numbers, we have no way to deport all the people who are subject to deportation orders, nor are we willing to fund our immigration and court infrastructure enough to allow likely asylum fraudsters to be detained during the hearing process then swiftly be deported.
On top of all these problems, there world is full of likely hundreds of millions of people who technically do qualify for asylum, no fraud needed.