For example, the new .config directory in the home directory.
I hope slowly but surely no program will ever dump its config(s) as ~/.xyz.conf (or even worse in a program specific ~/.thisapp/; The ~/.config/ scheme works as long as the programs don’t repeat the bad way of dumping files as ~/.config/thisconfig.txt. (I’m looking at you kde folks…) A unique dir in .config directory should be mandatory.
If I ever need to shed some cruft accumulated over the years in ~/.config/ this would make it a lot easier.