I do not get what this argument is about. I will reiterate the point that generally speaking abundance of magic items favors the character who do not cast spells. The less magic items in play the greater the comparative power of wizard.
Well, my bit of it is about the Primacy of Magic as the unique Essentially D&D element missing from 4e.
And that ties into the fact that magic item abundance tends to favor classes who lack magical abilities, themselves, in the sense that the fact supports the supposition. In authentically-D&D D&D, classes with magic are superior to those without, but that disparity is equalized by sufficiently available, class-specific, and powerful magic items.
In contrast, 4e, lacking the Primacy of Magic, could do without magic items by flipping on inherent bonuses, and the mundane (martial source) characters would still be reasonably balanced with the supernatural (Arcane, Divine, etc) ones.
It was really good at heroic fantasy. With strong scene framing and good handle on skill challenges it could be used to play out some really epic fantasy. This really plays out well with the thematic material attached to Paragon Paths and Epic Destinies. It was horrible at dungeon crawling and conflict neutral play. Unfortunately they decided to make almost all the official adventures dungeon crawls.
Conflict-neutral play?
Dungeons weren't automatically horrible, it was the 'Crawling' that was just tedious* compared to the other modes of play you mentioned - unless you abstracted the crawling into a Skill Challenge, then it was fine. I figured that out early - but converting Temple of the Frog really drove it home. Trying to have players map that thing was a nightmare, having them make a series of decisions and checks to explore the area and string together the otherwise random combats, though, worked nicely.
It was really good at being what it was.
So, an Epic Heroic Fantasy RPG?
It was really bad at being Dungeons and Dragons.
Heh.
Heh, but, then we run into actual play.
No DM is ever going to simply hand out 8 +1 swords. At some point, that +2 sword is going to slip in. Then a +3. Then a Sword of Sharpness or whatever.
Well, and if you do end up with 8 +1 swords you can pretty quickly recruit 8 surprisingly loyal low-level-fighter henchmen, and carve up some magic-weapon-to-hit monsters. Oh, some of the henchs'll die, but the swords'll still be there...
The change in 3e was that the rules allowed the players to be specific about what they added to their character. But, in terms of actual power? Naw, AD&D gave TONS of magical power to the party in terms of magic items.
True. 3e actually slightly reigned in magic items, slightly. They became less arbitrary and more consistent with the power of spells. Still hugely powerful, vitally important, could be quite character-defining, but didn't quite rise(?) to the level of character-overriding they could in the TSR era.
* it's not like a dungeon crawl being tedious is doin' it wrong or anything, it's just contrasted with other, non-tedious adventures, they kinda stood out.