Potion of Decay (again)

I am once again asking for Mojang to implement a potion of Decay in survival using the Wither Rose as an ingredient, or by using a fermented spider eye on a regeneration potion, the potion roster feels empty without it, even if you feel the need to nerf it, please! I feel like other suggestions using Nether Stars or Wither Skulls are too expensive so Wither Roses seem the most reasonable and seem very intuitive.