When they had all had enough to eat, he said to his disciples, “Gather the pieces that are left over. Let nothing be wasted.”
This indicates the abundance of the provision of Jesus for the needs of the people. His provision of resources and grace is inexhaustible to the point of having a large surplus.
Notice that “all” were filled. Jesus did not discriminate against anyone. Everyone who was hungry was satisfied.
The excess would have been given to the poor.