I thought you meant "what are thousands of other people supposed to do" which sounded to me like you were saying its unfair that they have to wait in line for something...?? which is my gripe... I say you should have to wait in lines every now and then for a MMO, that's part of the experience, it adds that element of realism and reminds you your in a world not entirely designed for you...
I miss the old days where questing took place in groups or small numbers inside a non instanced area (dungeon) and the open world was there for grinding. Thats how I've played Skyrim for a year and a half and I've not completed a quest past Whiterun.
Run from 1 dungeon to the next and clear it out, explore and find treasures.
Hell yeh! Children make the best evil minions by far.
("Children are the future.... scared?")
I have been playing a game that is just like you describe for nearly 6 years, not one instanced in the game and over 100+ dungeons. Some are vast and take days if not weeks to do and span many levels. The world is vast and open with 19 races and 16 classes, 18 if you take the three in one class of the shaman.
WoW, you're demanding.... BTW, like most MMOs, in ESO theres multiplle ways to complete (some) quest. Also, theres quest with choices with concequences. So yep, its gonna be awesome, dont worry about it, I bet you dont even think about that knd of stuff when you're playing this game. This is true triple a MMORPG, nuff said.
Easy solution.
Upon freeing your 20 childred, have a short countdown. Like a new jailer is comming, and you have 30 seconds to free as many more as you can, and you get a slightly better reward the better you do. This way they can maintain their cut-off point, and still allow a level of depth to those types of quests.
Guild Wars 2 does this with their collection world events. and the required amount is raised depending on how many people are involved.
Developers do have the ability to allow players to see their own version of NPCs. To take the example from the OP, it wouldn't be impossible for the developers to "turn off" the graphics for the children, for any player who has successfully freed the number specified by the quest. The children would be in the world, but the graphical representations would only show up for players who had not completed the quests, yet. Once you finish the quest objective, the cages would appear empty to you, as if you had freed everyone.
It does take a bit of work to program this sort of thing into every quest (not necessarily in terms of difficulty, but the sheer number of quests in the game means there's some significant man-hours involved) but it's possible to do it if enough players want it. SW:ToR-like Instancing is not required for this to happen.
-Travail.
The act of resetting, implies there is an instance/phase there.
I just played the start of Neverwinter Nights. There is a quest that says to go heal 3 soldiers in a battlefield. Once you heal three of them, all the rest you come across have died.. So it felt like you only had time to heal three and the rest died from their wounds. It was done very well. It did not even feel instanced.
There were others on the field trying to heal soldiers as well. However, all you see is players bending over the soldiers. So, from my prospective, I just thought, too bad he was too late. But to that player, he is healing that guy. Worked very well.
That has to be the best sort of solution, could requires some ingenuity in some scenarios, but mostly would be possible.
I would note that in WoW there are often quests where you can keep saving people if you want to but you don't get any more credit for it, which works ok too.
They already stated that e.g. rearranging objects is only to be seen client-side. Same could happen to quest-NPCs or items, so I am pretty sure TESO has a better system than WoW or the in this regard horrible SWTOR.
Yeah, a lot of people don't realize that instancing, when done right, can be great. It does not have to separate players. It can actually bring them together.