Jesus didn’t tell us to pray, “Give us our monthly bread.” Or, “Give us our yearly bread.” That would have made life easier! God wants us to trust him to provide just what we need for each day. Jesus knows we risk forgetting God if we don’t rely on Him daily.
God wants us to live free from worry. He wants us to trust him. He wants us to talk to him everyday about what we need. When we do he will provide, but more importantly we will grow to trust him more. Of course that was God’s intention from the beginning.