The smartest character in the GoT during the past seven seasons that deserves the Iron Throne is:
Remember GRRM said it many times that the GoT will end
'bitter sweet.'
He had also said:
"My biggest dream was to ruin the lives of my readers and crush their souls"... And I really think that worked out pretty well for me. - George R. R. Martin
Who ever you really like consider them dead by the end of Season 8.
Perhaps the Night Walker will take Cersei as his dead wretched old bride -
Consider it the 'bitter' sitting feebly on that cold spiky Iron Throne.