Well, Sacksmas cards are finite and will go away in a couple weeks. The in-lab menace reduction is one of very few ways to relatively straighforwardly reduce menaces without relying on chance, spending echoes, or also increasing a different menace.
So, actually, since entering the lab is now free, it’s incredibly valuable to be able to reduce menaces at will.
Further, reducing menace via potions is trivial when you’re endgame. Which is when you have the lab.