Unlike the subjective nature of "Easiness" and "Hardness," "Simplicity" and "Complexity" are objective concepts. "Simple" refers to an uncomplicated, one-fold structure, while "complex" means a state where multiple layers are intertwined. Easy/Hard are relative terms, and people choosing what seems easy doesn't necessarily guarantee a simple structure.
For simplicity, instead of interleaving complex structures, separate components and then compose them to connect simple elements.

Seonglae Cho