Neither 7-Zip nor DMG Extractor are the ultimate solution, though. There are some DMG files that 7-Zip, nor other alternatives that we've tried will open.

Pacifist is a popular file extractor for macOS that lets users view and extract multiple file formats, including PKG, DMG, XAR, and TAR.

It extracts files that are hidden inside other files stored on a Mac’s hard drive. The app offers the ability to extract JPG, MP3, GIF, and many other types of files that are embedded inside PDF files ...

The archive utility Springy has been updated with support for DMG and ISO files and much more.