Changing Author to Reader - is there really no way?

I saw lots of posts regarding this issue, is there really no way to move authors to become readers?
I do not want to delete accounts and add them back due to permissions and groups.
Any Help?

There is no way to do it in the QuickSight console. I don’t know why. I will mark this as a feature request.

However, you should be able to do it with the AWS QuickSight CLI.