While this does look made for earthbending decks, the reality of the matter is that this is way more oriented into doubling mana dork mana in other builds
For trading cards, theyre a liability
The current bid is at $6.3M, already making it a two-time Guinness world record setting collectible
Boosts the card sleeves' ruggedness and longevity for lasting performance
Relic of Progenitus was first and likely remains the best one-mana graveyard hate artifact in existence, though Scrabbling Claws also effectively does the same thing that the Furnace does, just better
Finally, if youre using low-cost ramp to make up for the fact that you dont have consistent land drops in the early game, then you need to run more lands and are objectively a bad person, both morally and spiritually