Death Is Now Meaningless in Game of Thrones
You cannot underestimate the power of the telling. We often talk about how good narratives are but it's the story - the way a movie/TV show/game is told and the meaning inferred to the plot - that makes it great. Imagine if Memento was told in chronological order or Up missed out its tear-jerking opening - you have the same basic plot but the core themes and story arcs are totally different. Game of Thrones is a mammoth story full of interconnecting threads of immense subtextual meaning. It's visceral and cerebral.
Perhaps the best example - both in what made Thrones great and what it's since lost - is death. Out of all the ways the show told its story, this was the most celebrated. Characters could be offed in horrific, unjust ways seemingly at random, defying convention and formula. But this was still storytelling with a clear purpose. After all, from a Season 7 perspective, that Ned or Robb were killed is by-the-by; we now know they clearly weren't the main characters but pieces of a much bigger whole centered on Jon, Dany and co. The skill was in making us think this carefully crafted narrative was random.
Now, though, death has lost all meaning. Plenty of people do still die, but they're supporting characters at best (and in "Beyond the Wall" hitherto unseen red shirts) removed to cut the fat. Main characters have a plot armor, even when their real armor threatens to drown them.
The last major character to be killed was Jon Snow all the way back at the end of Season 5, and that felt like a cheap trick when he was resurrected two episodes later (an early sign of these problems). Before him it was Stannis, meaning the last truly essential character to be killed and stay dead was over two years ago. Seven named characters went beyond the wall on a suicide mission and only the least recognizable or important one bit the ice; everyone else got thrown into feigned threat but came out alive. Like fellow kill-fest shows Lost and The Walking Dead that loved to proclaim "nobody is safe", Game of Thrones appears to be too enamored with its characters to truly test them.
Of course, this is also the product of Season 7 being the penultimate year; we're in the final act and so whereas in the Battle of the Five Kings the plot was a sprawling uncertainty, we know what the true end goal and who its key participants are. You can't kill Jon or Dany or Tyrion or others because they're the center of the War to Come; sure, they were always the clear leads, but now there are no other disposable mains to distract from that.
Thrones is, by its creator's admission, a classic fantasy tale reimagined, and so a finale with a set roster of characters would happen. But the show is offering little of that subversion as it goes and seems to still want the tension of its younger self - in the past handful of episodes Jon has been in a deadly situation five different times (taking on the Boltons and almost crushed in "The Battle of the Bastards" and surrounded by wights, almost drowning in ice water and again surrounded by wights in "Beyond the Wall") and each time is saved by a well-timed plot device (the Stark army, the Vale army, dragons, impressive lung capacity and Benjen respectively). There's no tension - he's already died once anyway - so perhaps there should be a different approach.
But death is just one part of the problem Game of Thrones is having with its ending.