You're right in that they needed more episodes.

The show made a number of poor choices in season 8 when you consider the prior seasons. I'll note just a few.

- The show set up the Night King to be a massive villain, with a history that influenced the world enough for The Wall to be created. This was a major theme since the first season. And after a battle where you could barely see, the NK was ended with a whimper.
- OK, well, that must mean that Cersei, who has always been shown as the most clever and competent villain, is the real Big Bad and the final fight with her and her forces will be EPIC. Nope, she dies quietly under rubble, after a dragon that the day before would have been shot down suddenly is able to avoid the scorpions that killed its sibling rather easily.
- Bran's character was criminally underdeveloped, ignored entirely for one of the recent seasons, and yet he is named the winner of the whole thing. Why?
- We endured Arya undergoing Faceless Man training for what seemed like forever - and it never came into play this season.

People watched this show for almost 10 years because the stories were so well-thought out and connected. And then at the end, when you want to see how it all comes together ... it doesn't. In fact, huge amounts of screen time turned out to be worthless to the climax. That was the issue.

BTW, Dany's coming madness was the only plot development that made sense. It's annoying that people complain about it. You can complain about the pacing, but not the story line. And then you could complain about the pacing for a lot of things.