What is it that you want in an MMO exactly?
A design that sustains playing for more than one month without artificially extending gameplay through grind aka "the journey"
Notice how I did not mention raids anywhere, I don't have the time nor patience for that model anymore
You're equating journey with "the grind" -- they are essentially the same thing
and not.
At the end of the day, everything is a "grind" no matter how you look at it. Things progress. Progression takes time and energy. Often, progresion is doing the same things over and over.
"Grinding" in an RPG, aka 0/10 rabbits killed for 1000 experience -- this is "bad design", but the concept of "grinding" is not wrong. A good MMO should have you doing various misadventures to progress your character, they should not be the sort of "collect X of Y and go to Z" quests you see frequently in WoW-clones. At the end of the day you're still grinding, but it's not the same.
For example, you could easily have it such that players
only obtain experience by killing a monster the first time it is killed and by making combat non-trivial. Killing a thief for the first time could yield 1000 experience, and the adventure of killing that thief could be intense (tracking down the thief, disarming the thief's traps, then engaging in the thief in mortal combat) and memorable. Instead of having to kill 20 thieves and collect their scarves to accomplish a quest, you accomplish a story-oriented goal a single time to advance your character. In essence, the mud Armageddon is sort of like this - if a player can go somewhere and kill a troll in somesuch place he's a bloody hero and noteworthy figure. If Armageddon were mainstream, it'd be a more lively game, because you'd have more players working together to "solve" it.
Ultimately, progression has to stop for your character, and the exact pacing of your character's progression is important -- it's critical that as your character grows. But, it becomes less about personal power and more about social power; this is the reason MMOs are MM and O. A good MMO transitions from personal power to players working together to kill entities much greater than a thief in mortal combat -- the main problem is MMOs don't leverage enough of this concept. What if a guild could obtain a large amount of experience by solving a huge mystery in the game world -- instead of having the quest giver indicate that Archimonde is responsible for the death of whosawhat'sit, the players have to gather evidence to conclude this, they have to uncover clues, find hidden alcolves in the world, solve smaller quests to open up stuff... A single player could not arrive at this conclusion alone; it's unlikely, but a group of them could solve this "raid quest" together. There's definitely an overemphasis on personal power and prestiege and not enough for groups of players to do besides play whackamole.
You might say that what I'm talking about, especially by suggesting making combat less trivial, that it's madness, but it's not something I've come up with; it's been done before and it's been done before well.