Because the way it works sucks.
I would expect, with 80% luck total, that I would get the 1st chest 90% of the time, the second chest 76.5+% of the time, and the third chest 61.9+% of the time, assuming the baseline chance of opening each chest is at minimum 10% for the first chest, 5% for the second chest, and 1% for the third chest, which I hope are the BARE MINIMUMS (they seem higher based on the number of times I get the third chest with NO luck perk).
While that trend was present for the first few CoF’s, the trend since then has declined greatly based on a sample of a hundred chests or so. I might get the 3rd chest 20% of the time. LAME!
Flare, what is the deal? Are the values perhaps not always registering? Do you hate me? (Don’t answer that; I know you hate me. But don’t hate me as much as you do.) Am I bad at math?
The math: Total probability for three chests = (Luck%+First chest%)*(Luck%+Second chest%)*(Luck%+third chest%)