because the rotation is just linear
it's long but it's a long corridor

compare with black mage whose rotation is very simple: fire 4 three times, then paradox then fire 4 three times, then despair, then blizzard 3 blizzard 4 paradox, refresh thunder whenever it's about to drop
however in practice black mage has a ton of decisions and paths to take when optimizing dps, to the point that there's 2 entirely different playstyles.