In africa it's mostly caused by wars and tyrants. You can't farm if you have missiles flying over your head.

In Europe, you have the awful regulations in Europe , that basically forces you to buy all kinds of insurances and vaccinate your animals, which is totally unecessary.

Besides you have a lot of farming land that is barren, owned by governments.

How can you feed people when you are not allowed to farm due to the excessive regulations and/or war.