Ethics and morals are in large part objective because suffering (different forms of pain, stress, and anxiety) can be measured objectively in certain ways. And perfect means of measure are not necessary.
There are objective overall differences in quality of life and meaning in one's life, depending on if the individual is healthy or unhealthy, authentic or inauthentic, toxic or constructive, and so on.
Some of the most obvious objective measures: cortisol in saliva blood or hair, inflammatory markers, heart rate variability, blood pressure and heart rate, amygdala activation, sleep disruption, cognitive performance, relationship stability, conflict frequency, and so on.