Inquiry Regarding Optimal Solution for Auditing Inactive IAM Users Across Multiple AWS Accounts

We are operating over 30 AWS accounts, each representing a separate environment. I access these accounts via switch roles.

As part of our internal audit process, we are reviewing IAM users whose last login dates exceed six months. While I understand that login activity can be viewed from the AWS Console, I would like to ask:

What is the most efficient and scalable solution for auditing inactive IAM users across multiple AWS accounts? Is there a specific benefit to using Access Analyzer for this purpose, even though login data is already visible in the Console? Any guidance or best practices for managing this type of cross-account IAM user audit would be greatly appreciated.