IAST reports findings in real-time for the scope of the app being exercised.
Many functional API tests are automated, making IAST a good fit for teams building in microservices, etc.
IAST avoids the need to re-create scripts for security testing.
Some IAST tools come with IDE integration to give you quick feedback on the features you’re in the process of implementing. This ability shifts the security checks to the left in the development life cycle when they are cheaper to fix.
Linking issues with code locations, IAST lets you click through your application to find problems and provides recommendations for quick remediation.
IAST doesn't require any application security expertise to use.