It's the last week of Dragonflight Season 3 and players have noticed that the Spiteful Mythic+ affix is doing about 60% less damage!
If you compare logs from before Patch 10.2.6 to after Patch 10.2.6, you'll notice that the unmitigated damage of a melee swing from Spiteful is now ~225k (down from ~600k). They also have about 60% less health!
This makes the Spiteful affix be basically just a nuisance that healers need to heal through rather than have any chance of killing players.
It's unclear if this change was intentional or a bug, but I'm leaning towards a bug. With the upcoming Season 4 change to keystone levels, affixes which previously capped at keystone level 20 (such as Bursting and Spiteful) would now cap at level 10.