The most significant benefit of measuring the results of a training program is knowing:

The ultimate goal of training is to impact business outcomes — such as improved productivity, reduced errors, or increased customer satisfaction. Learning and behavior changes matter, but organizational performance is the true ROI.

Extract from HRCI-aligned HR knowledge (Learning and Development):

SPHR candidates must link LandD to strategy: “Training effectiveness should be evaluated based on its measurable impact on key performance metrics.” This aligns with Kirkpatrick Level 4 evaluation (Results), the highest standard of learning impact.