As discussed in privacycg/storage-partitioning#11 it's complicated already and in a partitioned future even less desirable. There's also very little advocacy in favor of it that I've heard raising this topic with people. Folks primarily care about storage (and that clearing all of it, including service workers and such).

We'll likely do this in Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1671182.