7zip from both a UX and feature perspective is awful compared to something like WinRAR, it is popular mainly because it provides good compression and is free, but beyond that it is eclipsed by WinRAR in almost every other front (outside of compression, the only other thing that i find 7zip good at is archive support - it supports a ton of formats including even disk images with support for various filesystems, although only for reading).

Even PeaZip has a (slightly) better UI than 7zip (and that one is also crossplatform, if you care about that stuff).