There is some probability that the applications you use today will be replaced at some point.

Both .config and .local are hidden directories as well, for no good reason at all. Replacing dot files with dot directories does not solve the problem of having perfectly legal applications trying to hide stuff from you. Using $HOME/cfg (or something) as your $XDG_CONFIG_HOME would indeed solve it - with a bonus advantage of seeing which applications use hard-coded configuration paths (and could be filed an issue about that).