How can I open 7-zip file on macOS?

The Unarchiver is indeed a great tool for opening 7-Zip files on macOS. But it doesn’t let you create or compress files into the 7z format. If you need to pack files into a 7z archive, you’ll have to use a different app, like Keka or B1 Free Archiver. It might be a little annoying if you're looking for an all-in-one solution. Sometimes, The Unarchiver doesn't automatically take over as the default app for various archive formats, even if you set it. You might find yourself still double-clicking files and getting the macOS built-in tool instead, which can just dive you into frustration if it doesn’t handle certain formats well.

In my experience, about opening 7-Zip files on macOS, there can be tricky situations with really large or complex archives. Sometimes, if the 7z file is packed with lots of layers (think a million sub-folders), The Unarchiver can lag a bit or even have trouble extracting everything smoothly. You might end up with some missing files or strange folder structures.