If by “configuring wifi by hand” you mean writing config files by hand, that’s actually not necessary with plain wpa_supplicant too. There is wpa-gui (or wpa-cute if you prefer Qt over GTK), which is basically a GUI frontend to wpa_supplicant, which makes adding new networks nearly as easy as with NetworkManager. But it’s a far less modern looking UI than the NM frontends.

The special thing about vim are the different modes. In a editor which does not support modal editing, you can’t bind a letter key directly to a function, or else you can’t type that letter any more.