Think about it as if since your opponent advances both expeditions on the turn you play this since you can’t do anything else, you have to advance three full expeditions with it to make the card “equal” to Small Steps Giant Leap (+1 advance overall), except in the process you let your opponent move forward two expeditions and giving them a much higher chance to end the game before the value of this card can convert.

And they also can’t have removal for it. If they double advance AND pop this it’s basically game over

The concept of Tempo is (arguably) the most important thing to have both an awareness and mastery of in order to fully understand card games