As a Spacemacs user, the idea is a distribution that harmonizes a package collection into "layers" for Good Justice.
Using the space bar to drive a text interface is a win over the stock emacs key chords, which wear out my left arm/wrist.
Vi's modal editing, once understood, is a general win, too.
Spacemacs blew my mind by setting up a Language Server Protocol (LSP) environment for python with almost zero effort. Not sure if SpaceVim is quite as broad in its feature set.