So did anyone but me actually play this?
It's been a sort of mixed bag in my opinion, like an 8/10 game with potential to either be a 10/10 or 6/10 game a few years from now.
The Good
The campaign - Well-written, builds up well, characters actually have motivations and personalities and flaws, doesn't rely on PC idiot-ball like D3, some really good VA (esp. Ralph Ineson of course), and some really nice revelations and cinematics.
The graphics - Astonishingly good for how well it runs. Ridiculous. Character models look great too. Here's my Druid, for example:
They also scale well - I can get it running at 45 FPS and looking decent on my Steam Deck, for example, which is kind of better than PoE does.
The controls and responsiveness - I have never played any ARPG as responsive, precise and quick as D4. Blizzard have always been better than other companies at this, and it's constantly overlooked, but it's a huge benefit and makes the game play better than it would otherwise.
The animation/feel of the spells and attacks - Again absolutely great, and just light years ahead of other ARPGs. Makes PoE look not great, and things like Grim Dawn and Last Epoch look like they were cobbled together by cavemen.
The Bad
The lack of support for most builds - A few specific builds have huge support from how the skill tree is designed, what Paragon boards are available, and what Legendaries/Aspects and Uniques exist. However, most builds, even most "Core" skills (which a build will revolve around) do not have much support. I imagine this may well change over time, but right now, it's not great.
QoL features - Blizzard have always had a weird problem where they start games out with way too few QoL features, and only gradually, grudgingly add them over a great period of time, and D4 is no exception. You have four small-ish stash boxes shared between all your characters, for example. That's it. That's considerably less real storage than D2R currently has! You can extract Aspects (i.e. new features for skills) from Legendaries, great, but then they go into a needlessly tiny inventory on the character, or into the stash. Other QoL features in general are entirely absent, and so far Blizzard seem to have the usual begrudging attitude re: adding them.
The flow of gameplay - Usually something Blizzard are masterful at and something D3 got very good at by the end, but in D3, in both the open world and dungeons, gameplay doesn't flow very well, rather, you fight for 5-30 seconds, then wander around for a bit (often much longer than that), repeat endlessly, and it doesn't feel right. Outside of events (which the game kind of doesn't want you to do by endgame - some you even basically auto-fail at endgame) and parts of dungeons where you don't get XP/loot (?!!??) combat tends to be a bit weirdly sparse, especially at endgame, where there's no real equivalent to D3's Rifts/GRifts or PoE's maps, because NM dungeons are not as fun/rewarding as either.
The Ugly
The Renown grind - You're supposed to find every single one of 180-ish well-hidden statues, complete 150-ish different dungeons (most not that much fun - though some a really good), and do dozens of sidequests to increase your "Renown" and gain bonuses. This starts off fine and then gets increasingly old and annoying. And next season, we'll need to do
all the dungeons and about the same number of sidequests (most of which are fine, but dull and trivial, apart from a handful with good stories) over again.
Respec'ing - In D3 it's arguably too easy to respec, but D4 leans way too far the other way for a game that clearly wants you to try stuff out. As you get higher and higher level, especially into Paragon, it becomes increasingly annoying to respec, and you can't save a spec, so if you decide you don't like the new one, you have to
Enchanting costs - Everything at endgame seems to have a fairly reasonable price except enchanting - i.e. re-rolling one stat on an item, which is truly insanely expensive, and can easily eat days of gold in a few clicks. This is I guess nice as a gold sink but feels absolutely dire given how many different things a stat can roll to (and unlike D3, it doesn't tell you what they are, either). Picking no change saves you a little money but not much.
Repeat uniques - Blizzard denies this is an issue but an awful lot of players are experiencing getting the same unique dropped over and over and over. And no-one seems to have not seen this happen. As an example, I've got 10 uniques so far. Sounds good right? Well, 7 of them are same exact chest armour - Rage of Harrogath (which as a bonus is bugged and doesn't work with all bleeds). I think it's fair to say that when 70% of the uniques I've got are the same unique that something is wrong. And that Blizzard is rejecting this is an issue is worrying.
Rocket tag - This is strictly an endgame issue, but as I get higher level and go to higher NM dungeons and so on, the game feels more and more "rocket tag" - i.e. either you rapidly kill everything, or you get exploded. I'm not playing a glass cannon either, but a Barbarian with serious multi-layered defences. I think extensive balancing can fix this - it did for D3, for the most part, but I note it because it's an issue.
Now most of what is not-great here is either semi-expected, and/or it's stuff that will likely change over time, as seasons arrive and so on. But a lot of it is stuff Blizzard is typically loathe to change, and which won't necessarily change for the better. A lot too will depend on how seasons are designed. If they're like D3's earlier seasons, which didn't change or add much, that will not be good, longer-term. If they're like PoE's, which add a ton, and keep what works, that could be great. Or Blizzard could do even better and build the story out with seasons, retaining content from the. But the new season starts in like, less than three weeks and we know nothing about it at all, which doesn't bode super-great.