How is Demetrius used to show conflict in A Midsummer Night's Dream?

Demetrius is the catalyst for most of the conflict in the lovers' storyline. Hermia's father, Egeus, wants her to marry Demetrius rather than Lysander. We can't know for sure if Lysander would have received Egeus's blessing if Demetrius hadn't also asked for Hermia's hand, but it seems likely that he would have. Because Demetrius wants Hermia as his bride, however, and because Egeus prefers him to Lysander, Hermia and Lysander cannot be together and therefore decide to run away. Helena uses this to get Demetrius into the forest and alone with her, where she believes she can make him fall in love with her again. Oberon sees Demetrius spurn Helena and decides to put the love potion on his eyes so that he will fall in love with Helena, but as we know, Puck misapplies the potion to Lysander's eyes.
Essentially, if Demetrius had not pursued Hermia in the first place, none of the lovers would have ended up fighting each other in the woods.