I agree with all of that analysis, yet after last week I'm actually looking forward to the next one for the first time in years. HBO quality makes everything better, but ultimately you have to tell a good story. The thing that makes GoT unique is the all out rejection of "plot armor." They were willing to kill the most important characters in what was ostensibly the middle of their narrative arc. They could genuinely surprise and shock audiences. IMO if a show makes you feel anything, that's at least very close to art. Well hard to do that forever... at some point you have to be left with a story. Really the only ending I could have imagined being satisfied with was Shakespearean tragedy. Anyone who survives has to live miserably ever after.
What they did with the white walkers was the low point of the series. Turns out their only purpose was to form this coalition then be defeated in one battle. Just a plot device with the bare minimum devoted to developing it. It feels like the White Walkers were an afterthought except that they were in the first scene of the series. I hear they are making a spin-off, maybe they want to import the mystery of the white walkers right into that show. Maybe the George RR Martin ending involved Bran doing a bunch of stuff but they cast Bran as a little kid and he grew up to be a potato of an actor. Anyways post battle of Winterfell expectations are lower. There are so many problems I don't even want to complain about the physics engine of Westeros. But I think they are making lemonade. They just surprised killed a dragon with railgun fire from stage left, Dragons were nukes and now they are bottle rockets, they sowed the seeds of treason in Dany's camp, they are setting up a fight between the Clegane brothers, but most importantly they destroyed EVERY SINGLE romance in the show. I like the new direction.