Seed dispersal is an annual problem for a lot of trees and shrubs. If seeds just fell down and germinated under the parent tree, they would compete with the parent for nutrition, water and eventually light. Trees need a way to send their seeds away to a new environment where their germination will not pose a threat.
One way to do this is to give the seed a tough cover and then wrap it up inside a tasty morsel of fruit that will attract birds and animals. The birds and animals eat the fruit, the flesh of the fruit is digested, the seed’s tough outer cover protects it from the fierce digestive acids and it is then deposited somewhere away from the parent tree, in a pile of faeces that increases the fertility of the seed-bed. Neat.
Humans are among the animals that trees use to disperse their seeds. The people collecting sloes for their gin or apples for their lunch boxes are just part of a system much older than they are. We like to think of ourselves as somehow separate but we need to remember that we are not.