Bleach: Thousand-Year Blood War is the final arc in the Bleach anime. This significant arc showcased the final war between the Soul Society and the hidden Quincy empire, the Wandenreich. Naturally, there will be many losses on both sides. In previous arcs, very few Bleach heroes died, but all that changed in the anime's grand finale.
Source:https://www.cbr.com/bleach-tybw-impactful-character-deaths/