I wish more apps would use #Flatpak, just so they don't clutter up my home directory.
@FineFindus did you check ~/.var/app and ~/.local/share/flatpak ? It even puts more stuff in $HOME over here
@agx Well the files needed for the application to run need to live somewhere. But I much prefer having these two directories (which exists anyways) than each application having their own (e.g. .steam and .mozilla).