Full disclaimer. I’ve never really followed D2 and LoD past the few years past release and I have no interest in playing D2R. I mean, I played and played D2/LoD, but not since 2007 or so.
To me, the gameplay is a little bit too stuck in the 2000s. A lot of players enjoy it, and that’s fine. Different takes for different people.
However, Diablo 2 itemization is VASTLY superior to whatever D3 and D4 have or had. There was a thrill whenever you found an unique (at least, it did for me) and to some extent, it does the same when I play PoE (and I know some people really hate PoE here, but itemization is much more in line with what the old Blizz did with D2 compared to D3 and D4). Runewords added another layer that was unprecedented at the time (at least, I think).
D3 itemization, I can work with. You get to max level fast enough for the endgame to be pretty much a matter of min-maxing, but you don’t get to care too much about your loot: It’s disposable and replaced by a better version every time you can. It’s easy, but a bit too easy/mindless for a lot of people. It doesn’t give a lot of gratification when you find a Legendary or set item, considering you’re showered with loot, but it’s fine in small doses and you may think I’m weird, but I enjoyed D3 RoS.
D4… Constantly leveling and finding new copies of previous items is even worse than D3 itemization and loot was, except maybe D3 release, but even there, I’m not sure. Add plenty of filler affixes (as in, completely useless for any build or surpassed by another affix that can roll on that particular item), and you’ve got the recipe for endless grinding without a lot of reward. All stick, no carrot.
D4 endgame is subpar, but it could get better. I hope it does. Itemization will be a hard thing to change though… I’m sure some people like D4 items and loot chase, but I don’t. In a loot driven game, this isn’t great and I might “shelf” D4 for a while after S1. We’ll see.