Software as a Service (SaaS) companies don’t adhere to standards for their databases and APIs aside from conforming to something like REST or SOAP. The proprietary data models and access systems can make things very difficult for integration.
Companies often use dozens or hundreds of SaaS applications which can be very difficult to get them to talk together. A unified API is an abstraction that allows us to combine APIs for multiple providers – giving us one place to access all of their endpoints.
It’s really common to connect to a unified api if your company is using multiple CRMs like Salesforce, and Dynamics for different business lines.