I have almost leveled all my 20 chars to level 50 and consequently have run the basic dungeons any times. Not once did I manage to convince people to wait for me to do the quests in a slow fashion so I can get the story. I still, after so many years of ESO, don't know the story behind fungal grotto I because people just rush thru and pull me to the bosses.
Sometimes this is so fast that the last quest point find/kill the peligars for instance is still open while the boss I should kill is already dead.
So I request - like so many before - to implement a story mode of the dungeon where one can do it solo even when low level char and which can be repeated but without the additional rewards of a skill point. The code for preventing quest rewards to drop exists already for trials. It should be not difficult to have this implemented for dungeons.