Doom Emacs has its own keybinding system. A more accurate explaination is Doom Emacs keybinding system is a wrapper over evil mode such that it is smoothly compatible with Emacs. If you use Evil mode without Emacs configuration framework such as Spacemacs or Doom Emacs, it is frustrating to know if your keybinding is setup properly and whether it will always work as expected in any circumstances. A common point of failure is when your keybinding is overwritten by some packages.