M365 security was designed to manage one tenant... MSPs manage more.
Microsoft 365 has no shortage of security features. Conditional Access, Defender, Intune, MFA, mailbox controls, identity management, and more give MSPs plenty of tools to secure their customers. What we do (or rather, don’t do) with these tools is what causes issues. These tools and settings must be configured correctly across every tenant, and we need to be sure they stay that way.