I interpret "works" to mean that it accomplishes its goal. For instance, if somebody threatens to break your storefront windows unless you pay protection money, so you pay the money, then the threat worked. We used to use a different word than "terrorism" for that, but you get the idea.

But you rarely hear that grafitti works. Or that road rage works. They might accomplish some goal, but that goal may be difficult to discern. So we tend to qualify the success. "If the goal is..."

If the goal of running a marathon is to improve personal performance...

When the point is unclear to say the least, it is pointless to say it works without saying what it works to accomplish. It's like saying, "dying your hair works."