Cain in the other hand did not bring anything to God, there was no loyalty in him, he felt he was wise and so he decided to bring the spoilt crop to God and God was really angry with him for lack of humility and loyalty and for that reason, God rejected his offering.
Loyalty Brings Connection
When you are loyal, people will accommodate you, they will always bring you close to themselves, you get to know importance people and get connections with them, They will feel safe to relate with you because they know you will not disappoint them and you will always be consistent.
They won't connect with you when you are hard-working but not loyal, because they know one day you will start feeling superior to them, because you feel all is based on hard-work.