(Disclaimer: I will work with absurd numbers here)

There is actually a happy medium, two in fact. Let's say that Ifrit's weapon drop rates are something that, by the laws of probability, it would take around 5738 tries for you to get all weapons. We all know that random drop chances are at the very least aggravating, you always feel frustrated when something simply does not drops or you get a token grade 5 dark matter. Yet we do not want to reduce the final planned amount of work to finish that content, after all we do not want it made 'easier', do we?

So there are two possible solutions: Currency, and Progressive Rewards.
Currency - Each victory gives you, say, 329 Tokens, for example. In order to acquire any of the actual desirable reward, then, you would need to trade in 5738*329=1887802 token for the item. That is still the planned number of victories, the same amount of work, but luck has been factored off the equation, everyone needs to work the very same and the duration of the content is the same. That, and players feel happy about filling gaugues and seeing numbers raise to a goal.

Progressive Rewards: So perhaps currency lets you skip all the stuff you don't want and just get the one item you want, and that would remove also the certain random factor of the thing that excites some people! So why not progressive rewards, then? We all want that beautiful Ifrit's Lance, it glows! And according to our previous guess on required number of victories, it'd it 5738 victories to have it for sure. Also we clearly do not want players to finish this too fast so- How about every victory gives a reward? But every victory AFTER the first gives a better and better reward. You probably start right there with Fire Potion, and each victory a better and better item until the last 7 victories give you the Primal Weapons! So it's like a filling gauge, each different reward is, perhaps, but a mere token and pretty useless, but you know that after getting that Blind Fish there's a Grade 5 Dark Matter and after THAT you start getting the Weapons! So you know that only those eight more victories and it's done! And hey, it was still 5738 victories in the end!

There is no actual need for true randomness, there is also no actual need to make the content faster or less spammable, it just needs to be more less aggravating, something that randomness does.