It's insane how many plotlines they end in season six. Almost every episode has a notable character dying so they can write out that part of the story and never mention it again.

Some have remnants that hang around for a few episodes as pointless characters who do nothing.

Episode 1: Ends the Prince Doran plot, and most of Dorne.

Episode 2: Ends Roose Bolton and Balon Greyjoy so their entire plots can be replaced by lame cartoon villains.

Episode 3: Ends the "traitors" of the Nights Watch story, and mostly abandons the Nights Watch story.

Episode 4: Ends the "Daenerys leaves, is mildly inconvenienced for a bit, comes back" plot.

Episode 5: Ends whatever the fuck Bran was doing.

Episode 8: Ends Aryas Essos plot.

Episode 9: Ends all of Daenerys in Essos storyline. Kills off Rickon. Most of the North goes away.

Episode 10 is the worst. It ends most of the complex storylines that made the show great. Arya halfway ends the Frey line, but then they do it against first thing next season as another shock scene. Basically 95% of Westeros stops existing.

After that they condensed the show into whatever characters they wanted to keep around teleporting around a few areas of Westeros doing things that didn't matter, knowing full well nothing they did mattered and their world was about to vanish into nothingness.

Characters like Lady Olenna and the Sand Snakes sticking around meant nothing. They were pointless characters who did nothing