Buying guidance
Identity is the control plane
Endpoint and email tools underperform when accounts linger after termination or when every SaaS app is an island. IAM platform selection is therefore a business operations decision as much as a security purchase.
Okta versus Entra ID usually turns on whether Microsoft already owns your collaboration stack and whether you want identity independence from that stack. Neither choice removes the need for application owner discipline during SSO migrations.
Limitations
IAM platforms cannot force vendors without SSO to behave. They also cannot fix shared passwords inside a vault you never bought. Pair this shortlist with password manager and PAM research.