Some of the "ideas" on this thread...
Look, wasting prep time is bad so wasting it on events that don't matter is bad.
Creating an elaborate mechanism that generates events that don't matter automatically with less prep time is bad, because it STILL wastes ANY prep time on on stuff that doesn't matter AND because actually the time you spent writing the events that don't matter generator... was also wasted prep time.
Doing what Chamomile apparently did and writing a vast mess of advice that may as well amount to "hey why not calculate exactly how many quests you need and write up EVERY quest/encounter for your entire campaign in advance?" is... still bad because at best you are gambling way to much prep time way too many sessions in advance, and at worst you are creating a shitty CRPG style experience, or even worse than the worse Chamomile just wrote a gigantic waste of time generator generator that merely generates an "events that don't matter" generator that in turn is a waste of time that generates events that are still also the majority of the time a waste of your time.
But even aside from all that... what's with the focus on events that don't matter? Off screen unrelated distant events in a "dynamic" game world are things that aren't just a waste of
prep time they are a waste of
game time too.
Resolving what the players do, informing them of the events actually RELEVANT to their adventures, and informing them of the actual consequences of their adventures are all things which matter, and which have real and significant time costs. Telling them about events in other places that are not the result of their actions nor likely to impact their actions is a waste of precious table time.
As such "dynamic" off screen information in ANY sensibly run game deserves and requires as little cost and attention as possible. "rumor has it the king of far away is sleeping with the dragon of kinkiness" is an off screen event you probably shouldn't waste ANY time on and should ONLY ever come up as a short off the cuff response to some attempt to gather actual relevant information that FAILED.
You shouldn't even need to have a prepared list of such things. You should be able to rattle that kind of dross off the top of your head and if you can't... you probably shouldn't be running a game at that point anyway. The MOST you are going to do with such off the cuff bullshit is remember it or record it as something you might LATER turn into something that actually matters, thus hopefully recouping your wasted game time with some accrued interest.
"But but but!" you say, "WHAT IF, the PCs go to some region and interact with things that have been going on off screen that they didn't know or care about until suddenly right now?" you say.
So the hell what. You
cannot adequately prepare for sudden player driven shifts in what is or isn't important in any given campaign. And if the PCs DO suddenly decide they need to skip town and travel to a place far far away and adventure there instead... you just generate that material once that becomes clear, and that MAY involve out of game prep time, and you do NOT care about it's "dynamic" off screen events before that moment in time that the players frame of reference shifts to it, BECAUSE it was flat out a total waste of everyone's time to tell them all the fuck about what was happening in far away land while they were previously only playing in right fucking here land.
Now on the other hand...
Offering a changing rotation of quests or plot hooks as the game progresses is fine, even ideal, but rather clearly if you think you can predict any further than an at best vague idea of the next set of hooks beyond what the players are currently dealing with before you see what the players actually do with the current set of hooks... you are running a pretty piss poor non-interactive campaign. Why the hell would you write each plot hook 4 (or whatever) ignored "steps" deep when players might nip it in the bud 1 step in? Or ignore it ALL the way through regardless?
OK so "you didn't deal with this quest early, now you MUST deal with it's consequences now!" is all very well like ONCE EVER, do you actually plan to do that with ALL the quest chains? Ok, most of them? Even any notable minority of them? Right, so in other words players can and by every right SHOULD ignore the VAST MAJORITY of quest chains in their entirety with absolutely NO consequences. Because you do not have the TIME nor the charity and tolerance of your players to make EVERY quest they do not take nag them repeatedly with status updates and then eventually jump in their faces and DEMAND attention and indeed for those same reasons you cannot even do that any amount of time that we could even come close to referring to as "Often".
If that is true, and it damn well is, what in ANY way is the value of writing up the future steps of ignored quests in advance compared to just writing up entirely new sets of disposable quests/hooks when players seek them out, or in relatively immediately prior prep time and just having some of those have some relevance to prior in game events/choices?