The modern security toolkit is varied by necessity, with different tools required to effectively perform different tasks. As part of a successful defense-in-depth strategy, often deep-dive analysis is needed to fully understand and respond to serious events and data breaches.
While not needed for every event and every investigation, Digital Forensics and Incident Response (DFIR) is absolutely essential for InfoSec teams dealing with sophisticated cyber adversaries.
Article Link: DFIR Demystified: Understanding Digital Forensics Incident Response