The changes to Sterak's Gage hit a lot of champions in a bad way. To ensure that their win rates do plummet too much, and still retain their intended roles, Riot are implementing changes to Deaths Dance in patch 12.4.
Since the Preseason 2021 item overhaul, light fighters like Irelia and Xin Zhao have felt a lot more like unpunishable tanky murderers than they really should, according to Riot.
When these kinda champs have too much of their power in health and defensive-skewed items, their high-risk high-reward playstyles get washed out and become reliable, low-risk yet still high-reward. They basically become frontliners that can singlehandedly murder you, rather than risky champions who have to be swift and smart going into fights in order to get their sweet, sweet payoffs. At that point, why would you pick Nasus when Riven feels just as durable and has better damage and mobility?
To de-homogenize the system, where very different champions use the same items due to being part of the fighter class, the developers considered adding new items tailored specifically for each class.
Recent changes to the Sterak's Gage were a step in this direction, by removing it from being a viable option for lighter fighters. Now, developers are moving Death’s Dance back toward hybrid physical/magic damage reduction.
The reason Riot give for choosing Death’s Dance, is that the item requires fighters to actually deal damage in order to survive the bleed. They can’t just sit on the front line and soak damage, waiting for the right opportunity to go in. Unless they fight with finesse, Death's Dance won't save them. This will ensure that tanks and fighters remain in their own separate roles.