This has basically already been proposed via the XDG (Cross-Desktop Group) Basedir Spec in 2014 [1].

The latest version of which can be found here: https://specifications.freedesktop.org/basedir-spec/basedir-...

And, of course, obligatory reference to https://xkcd.com/927/

[1] surprisingly hard to find history, but Wayback Machine to the rescue: https://web.archive.org/web/20170319100840/https://specifica...