There are so many issues with the last episode.
Why burn all the food? The people need the food, too. But even if you don't worry about that, don't Danny's troops need to eat? They got a good early winter crop going over there on Dragonstone? I mean, she smashed the forces protecting the food and had plenty of Dothraki there to haul it away.
And what about the presence of the ballista. Wasn't Jamie already on his way to Highgarden when Cersi was shown the device for the first time? How'd he get one?
GRRM is very meticulous when it comes to internal consistency and presenting brilliant strategies used by the various characters. Without his novels to work from I feel like the show writers just can't maintain that universe at the level we got in the first several seasons of the show. The more they wander away from GRRM's work the more it feels like a fantasy show about magic and dragons. I don't typically watch those sorts of fantasy shows. GRRM created a rich enough world and rich enough characters to sell the magic and dragon stuff to a very wide audience. But that's why he's so good. That's not easy to do.