I disagree. Season 6 was jon’s Season. He had a great arch. It did the bulk of the work making him the main protagonist, and the season had some incredible scenes. 5 is probably the worst season but it’s still far better than the bulk of television.
What specifically made season 6 terrible to you? Can you give some examples?
Personally, I didn't care for Jon in season 6. He learned absolutely nothing from dying and kept making one wrong decision after another. I also didn't like how spineless he seemed with Sansa, letting her walk all over him. The Battle of the Bastards was just as mindless as Beyond the Wall. No sense of tactics; bodies piling up for no reason; Jon's extremely idiotic and out of character behavior; Sansa "saving" the day with an army she told no one about, and then her sick enjoyment of watching Ramsey being eaten alive.
Sansa in general has been an indecisive annoyance ever since the end of season 4. She's stupid, arrogant, conniving, everything I thought she had grown beyond after season 1 (same goes for Daenerys). Her conflict with Arya in season 7 is probably my least favorite subplot in the entire show. Either they were faking it, which means the show lied for multiple episodes, or they really were that stupid and almost killed each other yet somehow figured it all out offscreen in some indecipherable way.
The Sand Snakes somehow smuggling themselves on Jaime's ship to kill Trystane, Ellaria killing Doran reeked off last minutes changes to appease fans who hated Dorne, when what D&D should've done was just sharpen their writing and make that whole subplot decent. All the crap with Arya and the Waif, especially the latter's Teminator-esque chase sequence (with Arya acting like a complete, cocky fool and allowing herself to get stabbed, shrugging off what should've been a fatal wound given its severity). In the end, Arya's time in the House of Black and White was basically a waste. All she learned was how to kill, everything regarding her training led nowhere.
The resolution of the Meereen storyline was likewise pointless. If all Dany had to do was kill the Masters and appoint a ruler this should've been finished at the start of season 4. The original reason for her staying there was to learn how to govern, something she never accomplished. Instead the writers wrapped everything up in a neat, unrealistic bow. Like so many plot decisions in the later seasons, they went for convenience and speed over nuance realism.
There were reveals that served no greater purpose. Nothing was made of Melisandre's true self, or Hodor's origin. None of the characters ever reflected on those events and it never affected things going forward. The way Bran found out about Lyanna was not only anticlimactic but handled very poorly and lazily, especially when they waited a whole nother season to reveal Jon's father.
Cersei should not be queen. She has no real power, just a single Kingsguard and disgraced Maester. Even having killed the key leaders of King's Landing, the remaining nobility would never cave to her, nor do they have any reason to. Jaime's dismissal goes against established lore, as if it was that easy to dismiss a Kingsguard from his vows Tywin would've done it decades ago to name him as his heir.
And that's just a sampling of my problems with the show. I could go on and on listing countless critiques.
