Attack on Titan's series finale isn't supposed to feel good - Polygon

AoT’s ending episode helps explain the anime’s approach to Eren and his misguided dreams. And his failure is supposed to hurt for viewers who believed in him.

Titans (season 1) - Wikipedia

Is 'Attack on Titan' getting a movie? No, but there will be a part three

Attack On Titan' series finale receives major update, attack on titans final

Attack on Titan Final Season Part 3 to air in halves as 2 long episodes - Polygon

Attack On Titan' series finale receives major update, attack on titans final

Attack on Titan: The Final Season Part 3 releases new key visual, shingeki no kyojin the final season

Attack on Titan: The End of Controversial Masterpiece - Anime Corner

Attack on Titan: The End of Controversial Masterpiece - Anime Corner

There is Nothing Good About Attack on Titan's Ending