Her are my two cents.

For all type and size of the businesses, having an IAM governance is important. This way password policies can be set up and enforced.

When the SaaS landscape starts growing, this governance becomes more important and mission critical. The attack surface of the business expands with the number of passwords needed to manage by the employees.

In the above picture SSO brings significant relief to IT and Finance managers with less management hassle and reduced risk scores on the business side.

For the employees, SSO integrations gives more streamlined and smooth experience.