That obsession with a clear objective, I think, bridges old-school fantasy and modern thrillers. A classic fantasy protagonist might carry a literal 'call to adventure' from prophecy, which is straightforward but can feel hollow without inner stakes layered on top. Contemporary stories really dig into that personal drive, and I sometimes find the more internal ones stick with me longer than the external quests.
For instance, a wronged protagonist seeking revenge can fuel entire trilogies, but what elevates it is when that need for vengeance corrodes their soul, making you question if the mission's cost is too high. Then there are characters driven by duty to a loved one or a cause bigger than themselves, which can be incredibly moving or frustratingly noble depending on the writing. The real page-turners for me happen when the character's personal mission collides with, or even contradicts, the external goal they're supposed to be chasing.
The mechanics of the mission matter less than the fuel. Is it rage, grief, a desperate need for redemption, or a simple, unshakeable promise? That's what I'm reading for, more than the action set-pieces themselves.