This. 7zip it's amazing in its own right but some UX choices are weird like by default double clicking a rar file will not open 7zip (vs WinRAR that opens the preview what's files are inside, like any other program). Here you need to right click>7zip>Open in 7zip.

Not a huge issue, but I can see someone who installed 7zip, think didn't worked and then install WinRAR.