I’m not sure that arbitrarily separating almost half of your player base from the other for content helps make the world feel bigger.
One of the appeals for me was that RIFT felt like a more polished WoW, basically WOW 2.0 like they had taken what made WoW work and improve it. Of course Trion was… well… Trion. But until the first expansion it was great, and then they started to drop all the cool things that made it so interesting.
The soul system is still the best implementation of spec I’ve ever seen though. Being able to have a spec for every situation was amazing. Like I recall on my Warrior I had two tank specs (one for raids, one for dungeons), a solo/farming spec, an AOE spec, a single target spec and a ranged spec (when it was added in Storm Legion). So if there was a fight that was melee-unfriendly I could just swap to ranged, if it was a fight with lots of adds I could use my AOE spec, etc.
RIFT’s world was so much ahead of WoW at that time too. Lore lootables everywhere? Dynamic zone invasions? Closing rifts as an alternative to pure questing or grinding or even raiding? Awesome.
The expansions didn’t really do it for me even though SL was still legit fun. Didn’t do much past that.
As someone who plays ESO now, faction only matters if you pvp, based on my very limited experience in Cyrodiil it’s:
Daggerfall>Aldemeri>Ebonheart
In terms of easy to hardest.
Blizzard should just do what eso did, allow everyone to group with anyone and allow everyone to communicate regardless of faction, and just have faction matter for pvp.
I have not been playing this expansion at all, but I am guessing this forced faction war still doesn’t make sense in the current wow lore.
it’s just one of those things, hell it use to be like that in this game. Kids rolled alliance and adults played horde. How true it was during vanilla I have no idea, but you would hear that all the time.
Aion had 2 PC Factions (Elyos and Asmodeans) and a third NPC faction (Balaur). The Balaur would attack the stronger faction who took over too many fortresses to even the playing field. Didn’t stop faction imbalances but did create some pressure to prevent the game spiralling completely over to one side (you WANTED fortresses because the vendors there sold vital trade goods and they gave you a base for PVP operations in enemy land).
City of Heroes: Homecoming has a ratio of 3 superheroes for every supervillain. Apparently Truth and Justice prevails 
As has been pointed out, other MMO’s only have faction matter for PvP anymore, and even then only when there isn’t a clearly lopsided faction balance.
Factions only really work when you have developers who focus on PvP or even have PvP design in mind, but most give up on it because it gets tiring hearing PvE players complain when you absolutely need to balance the game and they have gotten used to being overpowered in their PvE environments.
Blade & Soul has 2 factions and actually blocks players from joining a faction when it is overpopulated – new characters can ONLY join the smaller faction and people on the small faction can’t faction change to the big faction until they become close enough in balance. Any race and class can join either faction.
But you can only PVP while wearing a faction uniform (it takes IIRC 10 seconds to change out of it) and opposing faction players wearing neutral outfits can PVE together. (Gear that affects stats isn’t visible in that game, except for weapons; outfits are basically whole-body transmogs.)
PVP base guards will attack anyone not wearing their own faction’s uniform, though – even if you are IN that faction, you have to suit up (which is the equivalent of flagging) before approaching.
Overall I think that’s probably a healthier system than WoW’s, but which faction you’re in plays a MUCH smaller role in defining a character. (Or maybe that “but” should be “because”?)
Hard agree.
I’ve still yet to see a decent argument for what factions add to WoW, beyond PvP … and letting people play PvE content together, across faction lines, would please all but the most faction hardcore players, who can’t stand seeing a single gnome, or orc in their dungeon that has nothing to do with faction warfare to begin with.
If WoW were a PvP-centric MMO, the factions would be a fantastic fit, but since Vanilla they’ve always been a clumsy, anachronistic feature that never added much of anything to the game.
There aren’t any, because the fundamental design goals are incompatible. MMOs are all about building up your character over months or years of gameplay and balanced PVP requires a level playing field at the start of each match.
That’s why Overwatch and other team shooters have only cosmetic “gear” and MOBAs with items that affect character power require you to purchase them during a match with resources earned during that match. Without those restrictions MMO PVP is an imbalanced clown fiesta at best, and I haven’t even gotten into things like CC durations designed for mobs first.