> an overengineered, overly cumbersome hierarchy under that.
You put config files in
$XDG_CONFIG_HOME/app/whatever with a fallback to $HOME/.config/app/whatever, and data files in $XDG_DATA_HOME/app/whatever with a fallback to $HOME/.local/share/app/whatever - what exactly is over engineered or cumbersome about that?
You put config files in $XDG_CONFIG_HOME/app/whatever with a fallback to $HOME/.config/app/whatever, and data files in $XDG_DATA_HOME/app/whatever with a fallback to $HOME/.local/share/app/whatever - what exactly is over engineered or cumbersome about that?