Why: one should not abandon the duty to which one is born, even if it is defective, since all undertakings are covered by some defect, as fire is covered by smoke, acknowledging directly that every path, including your own suited one, will have some real imperfection built in.

In life: waiting for a perfectly defect-free version of your own suited work or role before committing fully to it is an unrealistic standard, every genuine path carries some inherent imperfection, this verse says as much directly.

Teaching: stop waiting for a perfectly defect-free version of your current suited path before committing fully to it, this verse explicitly states every undertaking carries some inherent defect, waiting for perfection is waiting for something that was never actually on offer.