I'm with the OP...but I don't know if "unnerfing" is the right term.
It sounds, and correct me if I'm wrong, that it's not a matter of having "powerful or useless" items...but items that "feel" magical...the "wondrous", the "fantastic"...again.
Yes, sure. We were all in campaigns in the pre-3e days where you stocked your character up with a bajillion magic items (a BAJILLION, I tell you!) that did everything from give you a place to sleep to make you un-hit-able to taking out Orcus in one shot.
The party that had 3 fighters and a ranger and ALL of them had a flaming sword and plate +3.
But that, from what I read/have heard, isn't what is "missing" from magic items in post-3e games.
There's a place for +1 swords (how else are you going to hit gargoyles or wraiths!
). And everyone, I hope, remembers that first "aw cool!" moment when your piddly level 2 fighter got his first magic weapon...or a 2nd level wizard got their first ring or cloak of protection (FINALLY! I'm not automatically getting hit by EVERything!)
Yes, they became a part of what made your character cool...but they weren't entirely your defining character. A powergamer is a powergamer in any edition and obviously will find/take advantage when they can. That's up to the DM to control/limit...if possible. It's not really the kind of thing that rules can provide.
I think, with the whole introduction of "crafting items" and the "magic wal-mart at the next town" are what did the most harm to magic items "feeling" magic.
There was no "wonder" anymore. There was no (or severely limited/eroded) "aw cool". Nothing the DM could throw at the PCs that they hadn't seen before. There was just "This is what I want. How many gp?"
Let alone the "entitlement" of what I understand to be 4e's system of a "wish list" or automatic "parcels" of loot that are player requested.
Get out into the world and try
to find what you want! Research, rumors, ancient legends...and if/when you are high enough level to craft your own...actually getting out to find the materials. Everything shouldn't be down at "Mortimer's Magic Emporium-orium-orium! Flash for cash, guaranteed! If it's not Mortimer's, it just ain't magic."
I am all for magic items returning to that magical feel.
And yes, some might have "AMAAAAAzING COSMIC POWER!!!!" and some might be [metaphorically] "teeeeeeny tiny living space." Another thing that it is up to the DM of their particular group to..."police" is not the right term...but adjudicate, I suppose.
Why begrudge the character who got the girdle of giant strength? Get some cool stuff of your own. "He has a 24 strength and I don't" is just whining to my ears. It's not about "balance." It's about being jealous...and, <duck and cover for the onslaught> being childish. It's a game, a game of magical heroes in a magical heroes' world.
They should be rare. They should not amount to the defining qualities of a character. But nor should they be something that you can duplicate by talking ABZ feats or just going up in level. Nor should they be something that, if they get taken away/stolen/lost/used up...the character just becomes "nothing."
I dunno where I'm going exactly with this...but yes, make magic items feel magical again.
Have fun and happy gaming.