I didn’t have the same problems with the ending that so many have had, although perhaps I was less invested in it having only started watching it in 2017 (although I’d watched the whole thing twice by the time the last season started) and have not read any of the books. It seemed obvious to me that Dany was going to go full on murderous dictator, it had been setup long before the end. Jon was totally unsuited to be King, especially in peace time, he had no interest in the boring job of being a good ruler. Sansa did want that but only in the North. Arya - also no interest. That just left Bran. His push out the window in the first episode started so much of what followed that it was appropriate it finished with him as King. My main issues with S8 was that it needed more time to properly explore the route to the conclusion. Also, too much action, not enough talking.
Dany’s fall really rankled me. I had spent seven seasons shouting for the girl. I get that all her restraints were removed - her Jorah and Missandei died, her Jon rejected her, his sister hated her, then Tyrion betrayed her.... but it should have been more subtle and taken longer. Foreshadowing is not character development.
Cersei’s end didn’t convince - a tower of strength for seven seasons, reduced to sobbing in her brother’s arms in the wreck of the city. It would have been more fitting for Jaime to have killed her to broker peace with Dany, bringing his Kingslayer arc full circle.