SSO improves security and control. IT can enforce multi-factor authentication in one place and remove a departing employee's access to every connected tool at once, instead of chasing separate accounts. It also makes new internal tools easier for staff to adopt.
For example, a new internal portal or AI assistant can use existing Microsoft 365 logins, so access follows the same groups and policies as email. The limit is that SSO controls who can sign in, not what they can see once inside. Permissions within each application, and within the data an AI tool can retrieve, still need to be designed separately.