Regarding the end of TV series in general, I always thought that Game Of Thrones ended up in the unenviable position of being both a TV show (with all the traits and constraints about what works and doesn't work in how to tell a story in that medium) and being the now sole vehicle for this grand saga and world that would be extremely difficult to fit into a TV series (and is looking like it might be too difficult to fit into a series of epic length novels that can actually be written).
GRRM was a TV writer, and when he set out to write a fantasy epic, he wanted to write something that was completely unadaptable and unfilmable, unlike his horror and other fantasy works. D&D convinced him that it would work out with modern technology and TV audiences getting used to watching sprawling TV series, HBO threw money at them, and all three parties are ultimately very happy with the outcome. The fans aren't happy. I understand the need to go against the wave, look for the good in the bad, and deconstruct the circle jerk of GOT ENDING BAD that's currently going on, but the displeasure of the fans is absolutely unprecedented, and I think any unbiased person will have to agree there has been a significant dip in quality even compared to the previous three seasons, let alone the first four.
We can disagree on the logic of the events - though I don't see why we would, when we have black-on-white evidence for their logic being "Dany kinda... forgot about the Iron Fleet" and "Arya comes essentially out of nowhere because we decided that's the coolest option". Not to mention the endlessly self-respawning Dothraki, which almost makes it look like three different people wrote their episodes and didn't even check to see what the others wrote before them. My biggest gripe with the last season is that they really upped the ante on giving actors they like ~big character moments~.
Ned got beheaded by a petulant boy king, Tywin was shot while he was on the toilet, and Robert got killed by a freakin' boar, but a pre-teen girl has to be evenly matched with a goddamn giant for several seconds and survive an almost certainly lethal blow for a bit, because she has to have "a great death". She would have been insta-pancaked by that thing in any season before this, because Game of Thrones isn't a regular fantasy series.
Arya can get the big kill and then be the person on the ground to witness the destruction of KL when even the horse she rode out on would have been the more emotional choice - but then Arya doesn't get so many minutes of action and scared-acting, and doesn't get to deliver her big killer line, which they probably thought was super badass.
The books are setting up pretty much anyone but Cersei to be the late game human villain, but D&D like Lena Headey so much that they want to keep her when all logic has expired, literally creating the problem of "why doesn't Dany just roll up there and one-shot incinerate the queen with basically zero allies who everyone should be hating" that they've been trying to solve unsuccessfully for two seasons. They gave her a crown she shouldn't have after her boy died, money she shouldn't have to buy mercenaries and peasants that should be revolting still on her side just to keep her in the iron seat. Yeah, the last book got a lot of shit for setting up new characters that will fuck shit up in King's Landing before Dany gets there, but it turns out that without a popular person to rule on some sort of precedent and new alliances being forged, you have a power vacuum that can only naturally be used by a person rolling in with a professional army, a savage army and three freakin' dragons.
Bronn is popular, so we'll have him teleporting from place to place impotently threatening other people and give him something in the end so that the people who like him can smirk and say "lol that's my boy Bronn for ya". The character who didn't know what a loan was in season 3 gets to control the kingdom's money.
On the contrary, the person who they know is the future king of all of Westeros gets left out of one season of the show entirely and then has a bare minimum of lines in the final season, when he should be the most important person there. Just because D&D aren't fans of magic, don't like writing any storylines directly connected to it, and aren't all that into Bran's character. Reading just one Bran chapter beyond the Wall would probably blow the minds of people who think portraying him like this is inevitable, but we agreed not to talk about the books.
The real Jon Snow would have had some Thoughts about all the shit that transpired. He is a clever, resourceful guy with a big heart, always guided by the teachings of his mentors, but not afraid to bend the rules a tad more than Ned, and that's why he is valued as a leader. And his death will probably change him, making him more guided by primal instinct, and angrier. But the only side of Jon D&D like is his broody side, and they like the "you know nothing, Jon Snow" meme so they will build up all other characters as strategists and leaders at his expense, and then write two lines for him to alternate in the final season of the show. Forget about Jon of the books, the Jon of the first few seasons would hardly recognize this guy. His final tragic act of transgression is flattened, because how can you not kill Hitler with a dragon who just needlessly killed half a million people. Instead of a controversial choice, it was an inevitability.
I don't wanna talk about Tyrion and Varys