Derek Carr is still top ten in QBR this season per ESPN

Totally fair assessment. It's just that in the realm of these mythical tiers, it's just an easier qualification to use "ring or no ring" to determine top tier and other tiers. For example, when the greats I mentioned were still playing, you had Ryan and Stafford winning here and there in the regular season, but no rings. (Of course, Stafford got his after a chance of venue).
by those standards.. Stafford is elite.