There are several reasons why we should use the superposition principle to solve circuits:
Simplification: The superposition principle can simplify the analysis of complex circuits by breaking down the problem into simpler parts. By considering each input source separately, we can analyze its effect on the circuit in isolation, without being affected by the presence of other sources
Flexibility: The superposition principle is a general method that can be applied to any type of linear circuit, regardless of its complexity or configuration. It can be used to analyze circuits with multiple sources, dependent sources, and non-linear components.