There will always be some limiting factor on crafting gear.
First it was materials, then it was energy and crowns, now it is radiant fire crystals and orbs. But does it really matter, and is the game better off with one over the others?
Let's say we got rid of the forge and made gear cost far more materials than they do now..... So much more, that it takes the same amount of grinding as it does now to craft and sure, they can sell materials or what have you in the supply depot. The benefit to this is that it makes individual levels worth more and gives them a unique set of rewards, the drawback is that it makes treasure boxes worth much less, which really upsets the balance among levels.
The real issue is not the forge, but that gear cannot be limited by any two factors. This makes the best solution something like one universal gear crafting rarity, combined with just the gear specific material in the case of event items but begs the question of what boxes or monsters will drop if not crafting ingredients.
They say that the slowest step in the collection process is the rate determining step. Regardless, the reason why we despise the forge is because it became the slowest step even for the rich and payable. The sheer cost of crystals in the energy depot has already completely if not mostly discouraged the purchase of it. For F2Pers the energy wasn't the limit anymore, but for P2Pers too, the forge is.
What rarities does, simply slowed down progression for everyone. Intended I supposed, but maybe too effective. So what do you suggest an alternative for the forge be then? A mechanism that allows normal progress for F2Pers but does not hinder those who still paid anyways? This is the crux of all MMORPGs, that it is undeniable that P2Pers are generally richer than the F2Pers, so how do you build a system to overcome that?