The decline of GoT is somewhat regrettable. As the show separated from the books, it became vastly less good. It just shows how unbelievably fucking hard it is to write something like that.
I didn't really appreciate this until I got at a point in my webnovel where more characters joined the scene. It's 1% as complex as GoT, but it became significantly harder very quickly. You can just nod along the first two seasons of GoT without ever being super impressed because every one thing seems reasonable, but constructing that is so hard
Anyway he exited the process and the remaining writers couldn't do it, understandably so. I don't think they handled it poorly given the difficulty of the project. E.g., what Littlefinger did clearly stopped making sense, but they gracefully got around having to admit that by having him die at a convenient point in time, and the scene where he does die is really good. Given the countless other examples of writer utterly trashing the former qualities of their own product, I would even say GoT did well. At the very least I'd say they only got one of the super important things wrong. really important things they didn't get wrong include:
* War is fucking horrible chaotic mess (the most important theme in GoT imo)
* Destiny is bullshit/you have to use intelligent judgment
* Magic and other supernatural stuff is mysterious
I also have more respect for the ending than I think a lot of people do
But despite all of that, it was still one of the greatest works of fiction ever created and it went downhill. And then there is the one super important thing they did get wrong, which is that the story should remain unpredictable and plausible. Characters received obvious plot armor and the show clearly receded into the familiar parallel universe where concepts like catharsis and fairness play an integral role in determining outcomes, the same universe that most stories take place in.
I think one of the worst scenes in the show is when Theon tries to persuade his fellow tribe members to go and rescue his sister but they refuse. He gets into a fist fight with some other guy who is clearly stronger and gets beaten up. But because he now has the forces of justified holy conviction behind him, he bounces back and kills the guy, then goes on to successfully rescue his sister.
This is utter bullshit. What should have happened here was that he gets into the same fist fight, refuses to give up, and the other beats him to death. That would have been the kind of genuinely shocking event that was integral to the appeal of early GoT.
Other examples include the people who die in the Great War. Every single death there felt like a part of the plan. None was shocking. What they should have done is let Tyrion die. Or John Snow. Or both.