I also miss grouping prior to end-game while leveling, excluding dungeons.
The only MMORPG I've played which required a team for numerous quests, some of which were essential to progress the game's story-related quests (and I believe those quests haven't changed much since then so it's probably still the case now) was Allods Online. But that game is pure scam, a real shame.
There's a good bunch of MMORPGs I haven't played out there mind you, so I can only refer to my own experiences with the genre. But I do notice that in the games I have indeed played it was either way too solo-friendly from the start or something happened at some point where the devs "changed the mechanics" and the natural flow of the game became more streamlined, less challenging, or wouldn't required much grouping if barely at all. Not only to reach end-game, but even to perform in it.
One example that immediately comes to mind is TERA Online (Rising).
I've played TERA Rising for some time, from the first day it became F2P until about two months ago, which is when I quit. At some point, a few months ago, they released a patch which nerfed BAMs to the ground ('BAM' literally stands for 'Big Ass Monster' in the game). Those were the only monsters that pretty much required a group, or at least three players or so to fight them, and they weren't even essential (they were linked to optional quests). Since BAMs were pretty much the "world boss" of their respective zones it made sense that they'd be challenging and couldn't be solo'ed at same-level. If you ever wanted to solo BAMs before that patch came out you had to be at least three or four levels higher (not to mention wearing higher-level gear from higher level zone quest rewards at the very least). And I also always considered BAMs the 'mascots' of TERA, it really added a unique visual and game-play aspect to the game, in my opinion.
They were also simply fun to fight (well I thought they were, most of them). Then that patch came out, and they nerfed them hard, and I mean really hard. In fact, all the BAM types in low level zones (until around level 50 zones or so) became physically smaller than their pre-nerf patch versions (which was completely silly). They now have significantly less health, deal a lot less damage and some of them got their rage attack frequency reduced (they would rage after some point during a fight, that part also got nerfed for some BAM types, not all of them, however). The 'BAM' acronym was later mocked and changed to 'WAM' by the community, which now stands for 'Weak Ass Monster'. I never understood the reasoning behind that nerf, those quests were not essential to start with, and many players would skip them anyway because they wouldn't bother asking in zone chat or even in their own guild for help to kill them. They were there, period, and if you happened to like fighting them even just for the heck of it, or possibly to grind for potentially good loot, then you could do it, everyone is happy, no?
So what would most players actually gain from nerfed BAMs? Well nothing, in fact it was more of a loss than anything else, but apparently the devs thought it wasn't the case, that they were somehow too difficult and impeded in the leveling process/speed of most players (seriously, what the hell). Side note, I did not quit TERA because of that BAM nerf patch alone mind you, overall I just got bored of the end-game. But I just wanted to bring an example of group-related content that got removed in 'favor' of... hmmm, of nothing really but anyway it got removed (on the TERA forums a lot of people like to mock the devs by saying that their solution to - any - problem is to remove something).
Bottom line is that patch pretty much removed the only reason some players would find to group during leveling, before end-game kicked in. To add insult to injury the "end-game BAMs" (those that simply roam in end-game level 60 zones) got their loot tables nerfed and even those also deal a lot less damage than before, so if you happen to be bored with the game's very repetitive end-game content and wanted 'a challenge' or possibly wanted to grind level 60 BAMs for some loot... well, too bad, go find something else to do. Now they're just ambulant clutter, they're literally useless. You can solo almost everything in the game now (of course that is prior to actual end-game dungeons), but it had always been the case anyhow before that patch came out, which is the point. That BAM nerf changed nothing and it never "accelerated people's leveling process", since those darn quests were never essential to start with.
But enough with TERA's example...
The point is I like it when a game gives you options, when it accommodates players' leveling/questing tastes by letting them soloing almost everything if they want, or by allowing them to group with others to complete quests even if most of that group content is optional. When devs go as far as removing that content probably in favor of a more "solo-friendly" experience... it gets repetitive fast. I liked Guild Wars 2 a lot when it first came out, but after some time I realized to my own surprise that I actually missed the trinity system (tanking, dps'ing and healing) but also found out that doing almost everything alone was pretty much contradictory to playing a Massively Multiplayer RPG game. If I want to play something solo I can just play... you know... a single-player game.
I've watched the Quakecon live stream for Elder Scrolls Online and besides the fact that the animations are absolutely horrid and make my eyes bleed I do clearly remember hearing that you can literally do everything solo in the game. It's basically another Elder Scrolls game "but online"... hmmm, ok? I wonder what would have been the difference between ESO or "a multi-player mode" in Elder Scrolls 5... unless ESO pretty much is ESV? Time will tell, but to me ESO might just turn out to be like Guild Wars 2 in terms of group-to-solo content ratio. I'm also occasionally playing DC Universe Online and Champions Online, both of which are also very much solo-friendly and only encourage grouping once you do hit end-game content.
Maybe RIFT is different for that, but I haven't played that one enough to know if there's any challenging group content or if it's just another solo-friendly MMORPG. There's a lot more I haven't played at all, such as EVE Online and Defiance, or The Secret World, and many others. I do recommend TERA nonetheless despite what I've said simply because it's free-to-play, you lose nothing by trying (if you've never played it), the same goes for any F2P MMORPGs you can get your hands on, just give them a try and maybe you'll find one that gives you the sort of group-related content that you seek.
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