A limitation of the Drive API is that you can only share files with one user at a time. Google Apps Script is synchronous – it doesn’t support the async/await pattern of JavaScript Promises and you therefore cannot run the code in parallel.
There’s however a simple workaround to help you share a file or folder in Google Drive with multiple users in one go in parallel using the UrlFetchApp service.
On Pulse Phil recently shared a snippet for changing a Google Drive file permissions from Editor to Viewer. In this example for Amit Agarwal you can see how you can make these types of changes for multiple users without slowing down your script execution time.
