SMN in T8

[Madoka]

There's no "opening our eyes"

Ifrit simply does not do enough increased DPS to outweigh stat boosted dot damage to begin with. 5 more ticks of 20% boosted damage every 3 minutes, 5 more ticks of 84 Int boosted damage every 7 minutes, 5 more ticks of your potent poison potion (static damage) for 2 potions per 3 minutes. Garuda also benefits from Foes which will be up for at least 2 minutes of the fight, and possibly 3-6 minutes depending on if you have 2 bards and if mages ballad is needed. Ifrit's dps lead is usually 8~12 dps, assuming garuda's dps is 90 and ifrits is 100 unbuffed, garuda ends up at 99 while foes is up, 108 with BV. If you have a mnk then ifrit is gaining from dragon kick for one of his attacks, if not then nope. So as an 11 minute fight at the longest, and assuming a minimum of 2 minutes where Garuda and ifrit are at least matched, we have 9 minutes of Ifrit possibly doing more damage. 540 seconds. If his dps is 10 higher thats 5400 more damage than Garuda would put out. We'll round up to 6000 for his enkindle dot and gaining more from rouse/spur than garuda.

In an 11 minute fight we will use Contagion at least 10 times. This is 150 seconds of more ruins. Ruin is a 2.5 GCD. In i90 gear your ruin should be hitting 200 minimum. In 150 seconds you can fit in 60 Ruins. 60x200 is 12000.
Every potent poison pot is getting another 5 ticks, doubling its damage from 250 to 500. We'll assume you got to use 6 in the fight for 9 minutes worth of CD on it. Thats 1500 damage normally, 3000 damage thanks to contagion. 1500 more damage over the course of the fight that wasn't there as well.
Now this is obviously not how your extra time from contagion always goes but after factoring in at least 75 seconds of either RS or Int potion boosted dots that otherwise would have expired I think you get a comparable gain it's pretty clear from a bullshit math standpoint that Contagion is doing a lot more than anything Ifrit is doing.