in case you were wondering where your players lack agency...
Yea, I knew this one.
THIS is why you would get a complaint of lack of agency. You literally took control of the PC on a whim - simply because you objected to how they were roleplaying.
This would anger just about anyone!
Though remember the player (still) does not know the reason and why it happened. It's not like I make a big announcement.
This has to be the #1 most egregious example of taking away player agency. This is worse than rocks fall you die.
This falls under "anything a player does not like takes away player agency"....or to put it simply: EVERYTHING takes away player agency. There are a bunch of effects that can effect or "control" a character in D&D. I don't agree that a DM can never use charm or hold or domination effects on a PC.
Almost impossible to find Dragon that leaves the groups wandering aimlessly yields a near complete lack of agency - and even if they are partly to blame for not finding/remember/using the clues, that doesn't take away from the fact that they currently have little to no ability to effect the campaign.
The players are "free" to do their dumb idea of "wandering around like idiots and hopping to bump into the dragon". I this not pure agency here?
I will agree that when a player character acts like an idiot, they have no ability to effect much of anything. A super dumb character watching a herd of goats does not effect much in the world.
Whether they are 'bad' ideas or not, it sounds like you are shooting most all of them down outright - another agency impacting move.
Right....another problem I have with the whole "player agency" thing. Some ideas will be shot down quickly: because not EVERY random idea a player says lets them alter game reality.
Like in a past game, group D, had the great idea of making a giant huge crossbow and then shooting the dragon when it came to town. Of course the PCs had no skills, abilities or magic to do this. It's flat out (near) impossible for the group to do. But even IF I was a "fan of them" type DM, it would still take at LEAST a year to build...way beyond the adventure timeline. And...again...IF I was a "fan" and they did build it......and, somehow, got the dragon in range...and IF they hit.....well it would only do some damage and would be unlikely to slay the dragon with one hit anyway. And...sure...maybe they could make a giant huge bolt of dragon slaying.....but you know regular hand held or fired weapons can do that.
-In short, your campaign scenario along with the way you DM has led to an environment where the players basically have to wander around in the wilderness in hopes of finding the dragon. They can't go randomly talk to townspeople, they may get possessed by a ghost and sit there doing nothing for an hour. They can't make plans to get an advantage of any kind because you always say no. And to top it off, they can't even wait on the Dragon to just come to them because you don't advance time.
Your being a bit one sided here.
Note groups A and B spent a lot of time in town doing things. Nothing "bad" happened to them. Group Z did not stay in town....and player Kyle wanted to ruin the game with his dumb "lets pretend to drink for six hours" move...so yea, he got possessed.
They can "make" any plans they want....but they can't change the game reality. The town alchemest does not have 50,000 pounds of explosives on a shelf for salf for 5 gold JUST as the group came up with the dumb idea to blow up the dragons cave.
And it's not like advancing time would have helped the group of wandering idiots....ok, time flies, game over.
I actually was leaning toward the players just being a bit too entitled and that you mostly ran a normalish game, but it's not them, it's you.
Oh no.