Which is more complex and abstract, integrated circuit or digital circuit?

Integrated circuits and digital circuits are not two categories. Integrated circuits are relative to discrete component circuits and digital circuits are relative to analog circuits. Today, digital circuits and analog circuits are almost all integrated circuits.

If it is complicated, both analog and digital circuits are very complicated, especially in circuit form. As for concreteness and abstraction, it seems that analog circuits are more abstract, while digital circuits are characterized by concreteness but dullness, and are purely a collection of logical relations.