One criticism frequently aimed at House of the Dragon is the show’s tendency to tone down its characters, portraying them as victims of circumstances, where in George Martin’s literary source their actions were driven by ambition or even downright spite.
In particular, look at the events of the last three episodes of Season 1, which culminated with Lucerys Velarion getting eaten by a dragon and the Targaryen civil war irreversibly starting.
In the book, everything indicates that Prince Aemond deliberately murdered Lucerys by unleashing gigantic Vhagar on him and his baby dragon Arrax.
At the very least, Aemond never tried to argue otherwise after the fact. He hated Lucerys for maiming him, and he acted on his hatred when an opportunity presented itself.
In the show, however, not only Lucerys’ death was the result of some immature bullying going wrong when Aemond lost control of Vhagar. But also this outcome – and nearly the whole war – is framed as a result of a fresh pretty misunderstanding.
Look at the final part of the family feast scene in Episode 8.
After King Viserys leaves, the conflict doesn’t immediately flare again simply because one impassionated speech from a dying King cannot erase years of enmity.
No, showrunners have inserted a specific trigger which pisses off Aemond to the point where he makes his mocking toast, not-so-subtly accusing Rhaenyra’s children of being bastards.
At that moment of the dinner, a roasted piglet is placed by a servant before Aemond, to which Lucerys react by sniggering.
In case you forgot, in an earlier episode Prince Aegon and Rhaenyra’s sons pulled a prank on Aemond, who back then was the only royal kid without a dragon of his own, by gifting him his own “dragon” to ride, Pink Dread, who was actually a pig.
What to Lucerys was a funny memory to Aemond probably was one of his worst experiences ever, comparable only to losing an eye, so that reaction by Lucerys makes him mad.
And this, again, means, that instead of irreconcilable differences in opinions on laws of inheritance and incompatible ambitions of power-hungry men and women the whole bloodbath appears to be ultimately caused by chidlish pranks and kids being meaner than they realize to each other.