One of the biggest threats to your cyber security are unknown network devices and hosts connected to your on-premises network or in the cloud. You must know what is in your networks to protect them and you'll need an asset management system to track them.
Once an attacker gains access, if your network is flat, then the attacker can easily move laterally on your network to find hosts that store PII and other sensitive data. Network segmentation ensures that there is not a free flow of network traffic.
The ever increasing number of vulnerabilities means that vulnerability management teams need to work smarter. It's key to prioritize software vulnerabilities, not just by the Common Vulnerability Scoring System, but by factoring in network location and asset value.