$XDG_CACHE_HOME makes sense as having a directory that you can just blow away without fear but the $XDG_DATA_HOME / $XDG_CONFIG_HOME split, while not entirely unjustified, causes more problems than it solves because a) it is not always clear what is data and what is config, b) peeople disagree on what is data and what is config and c) other operating systems don't make this distinction for application files so ported software is almost guaranteed to just pick one and call it a day - so in practice you have both config and other data spread between ~/.local/share and ~/.config.