Harry Potter major character deaths:
Quirinus Quirrell, Barty Crouch, Cedric Diggory, Sirius Black, Albus Dumbledore, Hedwig, Alastor Moody, Gellert Grindelwald, Peter Pettigrew, Dobby, Fred Weasley, Remus Lupin, Nymphadora Tonks, Severus Snape, Nagini and Voldemort. I added some names who arent super major characters, but they drive the story forward in a major way.
GoT season 8 major deaths:
Dolorous Edd, Lady Lyanna Mormont, Theon Greyjoy, The Night King, Jorah Mormont, Beric Dondarrion, Melisandre, Missandei, Rhaegal, Varys, Qyburn, Sandor Clegane, Gregor Clegane, Jaime Lannister, Cersei Lannister, Euron Grejoy, Daenerys Targaryen
See, 1 more death in GoT season 8 than in all the HP movies combined ;)