Why do quantum gates accumulate noise across long circuits?

Example Concept: Quantum gates are susceptible to noise because each gate operation introduces a small probability of error, which compounds as the number of gates increases. Decoherence, the process by which quantum information is lost to the environment, and gate infidelity, the deviation from ideal gate operations, are primary contributors. These errors are modeled using noise channels like depolarizing, dephasing, and amplitude damping, which affect qubit states during computation.