In case the size of your PST file is larger than 100 GB, then you can use both solutions i.e. you can increase the maximum size limit for .pst files and then compress the file.

Smaller file sizes. Because they offer file sizes that are significantly smaller than comparable Microsoft Office 2003 files, the new formats will reduce data storage needs and costs for customers.

The .docx file essentially acts as a .ZIP folder which is able to compress a substantial amount of data in a file of a rather small size. 4] Don’t store a thumbnail for your document ...

The company has increased the upload file size limit for Microsoft 365 from 100 GB to 250 GB for uploads going into SharePoint, Teams, and OneDrive. In July, it raised the limit from 15GB to 100GB ...