I am going to attempt to put a positive spin on this card by trying to identify its most apparent niche.
Spell events are great. I love spell events. They are typically really impactful, but they're also really expensive. So lets say Luke Robinson wants to run Dayana Esperence with Read the Signs, but that's some pricy tech, you gotta muster up 2 resources every time you wanna do that. But by spending 4 resources and 2 actions, you can make this combo pay for itself. That's something, sort of.
And you can apply Fine Tuning to these cards, so you can trigger them twice per turn. That means that for 8 resources and 2 actions you can generate 4 resources per turn dedicated to playing spells. Not the worst engine, and it only costs 2 XP and 4 card slots. Getting the startup money is hard but not insurmountable, and if you're gonna be playing a lot of spells and getting a lot of clues then it will pay off.
Consider Prophetic. For 3 XP and 3 Resources you can get 2 resources per turn that can be spent on Spells, Fortune, and Spirit Cards, and can alternatively be spent on boosting tests on those same cards. Two copies of Mortar and Pestle is 1 more resource and 1 more action to play and requires you get clues to acquire those resources. Is Prophetic Clearly better? Yes, absolutely, but it also costs 3 XP and is restricted to Level 3 Guardian/Mystic/Survivor access. Mortar and Pestle can be taken by anyone with level 0 Seeker access, has synergies with other Seeker cards, and can bank its resources for later turns, something you can't do with Prophetic.
Is this an auto-take for 99% of builds? Absolutely not. But it's a card that I think you can extract a lot more value from than it first seems, especially if you're running Dayana Esperence and can reliably get clues.