Ideally, I'd rather not have 'quests', but 'goals' that can be achieved using existing game mechanics with muh story events working more as rewards (along things that affect the game world) rather than a thing you get showered with on every corner.
You see, this is the crux of the matter. The entire problem of a design called "quest" is based on the idea that Heroes of legends did them. Perseus went on a quest to slay Medusa with magic items, Jason created a party to get the Golden Fleece and the Round table quested around to get a Holy Chalice. This is not a bad design at all. It is just that it is the only one in most cases. And thus, the goal is foisted upon you without any real motivation. At least in the stories, the goal is a necessity; Perseus and Jason have been assigned their tasks to claim their birthright and for the Knights of the Round table it is a spiritual duty as well a quest for *fame*. But in the computer game, you do quests because they are added to your journal. Often, they are ill-written and present little if any conviction as to why the player must or should do them. While optional things like that are fine, they are perfect incubus when presented as a *necessity*.
Somehow this is a narrative structure that very few games seem to be capable of breaking. However, now there are more and more of them recently. And I believe they represent a step in the right direction, where the player decides what constitutes a quest.
I present the Expeditions series as a clear example, where for illustration, you can recover the Sword of King Arthur, arguably the most powerful weapon in the game, as a completely missable side-"quest". It is not even a real quest as there is no indication that this is the final reward. You simply notice some runic stones; pardon me; menhirs, and from that reconstruct the path to a hidden location where you might wander to just explore. There, on the island of dem apples, you may recover the weapon conditioned on your previous experience in the game; if you are the rightful king of the Bretons you can pull it out of the rock.
Now that is a brilliant design. Why? Because it gives you, the player, the initiative. It does not present even a goal or a map marker. It does not have the allure of a reward. You just decide if you are intrigued by the evidence or not.
Thus, if the developers can write *compelling* leads to a hidden target, I would consider that in general as the best design in lieu of the "Quest" structure.