If you love MMOGs then you'll disagree with everything I type. This is not Diablo 4, this is a new entry in the Diablo universe much like Diablo Immortal, which is fine but calling it Diablo 4 is very misleading, it is most definitely not a sequel to the line of games we refer to as Diablo.
Diablo, for me, has always been about the story, about becoming THE hero, saving the world from which ever demon raised it's head. It's about progress and immersion, and building your character. Without a solo mode, without the ability to actually clear an area and move on to the next one, there is no sense of progression, as an example the area you just walked through suddenly respawned all it's enemies, sometimes while you're still standing there, there is no sense that you're actually accomplishing anything. With 20,000 other people running around everywhere there is no way to become immersed in the game, you are constantly reminded that you are just 1 of a million people also doing what you're doing. It's really a shame.
The graphic are awesome, the game play is really solid. There is actually a story but it's interrupted constantly and you forget about it, back to no real sense of progression.
I do think the Bosses are over powered, you go from being relatively competent (might die once in a while) to suddenly you can be killed in 1 hit. I've seen this comment on many forums and I think that will be adjusted over time.
The loot system is also perhaps too generous. I am at level 43 and have over $3M gold with nothing interesting to spend it on.
So if you want a game that you can jump on with your buddies and kill lots of monsters in spectacular fashion, this is your game. If you actually wanted a Diablo 4, true to the game's legacy, this isn't it.