- No illogical character 180s
- Far more tension up until the last episode (everyone and their dog knew who would die)
- Fewer dropped plot points
- We get benevolent queen Daenerys/Arwen and future king Jon/Eldarion
Obviously no chance of GRRM ending the books like this, but it's nice to dream.
I just don't think benevolent Dany was ever at all going to be possible. Now I haven't read the books, but even in this series, it's been shown repeatedly that she has always been willing, eager even, to take things a little too far to prove a point. I don't think it was necessary for her to so rapidly go all Mad Queen and burn all of Kings Landing, but in the truncated high-pace season they not only have to show her acting as the Mad Queen, they have to make the transition to it all in the same episode for some unknown reason. But the plot pacing was definitely part of the problem - closing the book on the Night King was far too quick
I don't think she should have been quite portrayed as the Mad Queen with an entire city's destruction, as I think her character arc should have properly ended having been perhaps a bit too bloodthirsty and vengeful. She needn't be mad to be bad, perhaps just a touch of madness.
But all the check boxes that drove her to finally cross any kind of line she imagined were all ticked - she's down a dragon (well two at that point), she's recently lost very close people, she fears she may lose her hold on the claim to the throne, and Cersei is being very Cersei. All those points may have been contrived and carried out too rapidly for the overall story, but I think the same conclusion would have been reached even if the show had full length seasons 7 and 8, and even perhaps a full length 9th season.
Some other complaints, like all the lore and imagery of the White Walkers meaning nothing in the end, or inconsistent magic, I think could all be explained by GRRM simply not planning to ever bring those back up in the end, or at least never planned for them to be important. There are certain aspects that point to an overall inconsistency of sorts in the lore, but that's not said as a slight against GRRM or any of the shows writers, it may have been just in keeping with the themes of the whole story. Sure the walkers were obsessed with imagery as signs, but why does that have to mean anything in the end? Just because something is brought up seemingly as a major plot point doesn't necessarily mean it needs to be closed. There are reasons for that, because life is like that sometimes. For starters, we've only been conditioned to that due to common tropes in story telling, but it isn't a hard and fast rule -- it's just incredibly hard to produce a highly successful work that goes out of its way to avoid any and all tropes, and that's because people find tropes pleasing in their stories.
There are certain trends that practically define the whole story of A Song of Ice and Fire, one of them being a willingness to just toss aside what were once primary protagonists and antagonists, and it was done often. This never really seemed like it should have ever had an actual primary protagonist that would save the day, this was something more like a journey through the history of a people and who rose and fell over time doesn't need to make sense thematically, it just needs at least a certain consistency in getting the characters to those plot points believably.
Unfortunately the final seasons may have had the major plot points right but they were just terribly ineffective at realistically moving the characters from A to B. That was covered earlier with the idea that GRRM is a pantser, or one who goes by the seat of his pants, as opposed to a significant plotter. But if he already had major plot points, that kind of weakens the argument too, but I suspect even most who let the characters write the story (Stephen King is well known for this too) still have major plot points in mind. There's always a little contrivance getting characters to the various plot points, but some are much better at making it seem like the only logical outcome. While others are obvious in that they consider the plot points as the driver of the story, characters be damned, the seat of the pants style of writers believe in plot points and themes just as much but they believe in character-driven storytelling to take us on that journey with them.