War was over. The Lannister armies surrenderedThose people didn't die in real life
It's war. Cersei sealed the fate of her people when didn't send troops to help vs the WW, then she kills a dragon, kidnaps Missandei, and executes her. She could have surrendered instead she pissed off someone with WMD thinking they wouldn't push the button.
Dany doing what she did makes sense to me. That's one of the only things I didn't have a problem with this episode.