I understand what the OP is trying to say, but I strongly disagree with the solution suggested.
For how I see it, the last thing this game needs is EVEN MORE wild variations in numbers.
Once again I think the Baldur's Gate model should be the one to follow: few distinct tiers in quality, with no level scaling or requirement, not too far apart in terms of stats to prevent insane variations, but with a broad range of secondary special abilities to make each one of the top quality items feel unique and valuable.
Well, I wasn't suggesting WILD ranges in numbers. Let's just call them moderate. We all know that the most important stat on an item is it's damage, so having like a 0-200% range would be quite detrimental (just look back at diablo 3 at launch...different genres, I know, but the same principle should apply). But something like a 0-30% range might be fine, if those 30% damage would come at a cost of a modifier like +stats.
That being said though, your idea of a solution is also worth serious consideration. The caveat here would be balancing the tiers properly, so that you're not incentivized to use your level 3 ring at level 20 (except for certain niche builds) - upgrades are a part of the (a)rpg genre after all, but too frequent upgrades causes items to lose any sense of tangible value.
Personally I would be fine with either approach. As long as Larian recognizes these issues and deals with them, one way or another.
