Bhagavad Gita, Chapter 3, Verse 19

Therefore, always perform the actions that are your duty, without attachment; for by performing action without attachment, one attains the highest.

Do the work because it's yours to do, not because of what it'll get you. That's the version that leads somewhere.

This is Krishna's steer for Arjuna specifically: not renunciation, but action done without gripping the outcome. Letting go of attachment doesn't mean letting go of effort, it changes what the effort is for.