Krishna says that (3.35) swa-dharmam (own-nature or reality) is superior to well accomplished para-dharmam (others nature or reality) even when the former is devoid of merit. It's better to die in swa-dharmam than to be fraught with fear in para-dharmam. This intricate verse creates more doubts than clarity in our minds.
In a sense, this verse is purely contextual for Arjun in the Kurukshetra war. Arjun has warrior dharmam till that moment and desires to be a saint in the next one. The chances for this change are bleak and Krishna is indicating the same in this verse.
While Dharma or reality is ONE, we perceive it in different ways like how the proverbial five blind men perceive the same elephant differently through their touch. If one of them perceives it as a tusk, that is his reality or swa-dharmam. The verse further indicates that one who perceives it as a tusk should keep pursuing his path rather than trying to adopt the beautifully presented version of the one who perceived it as a leg or a tail.
The next question that comes is whose perception is the correct one. All of them are correct in their own way and that's why Krishna doesn't encourage comparison when he says that follow swa-dharmam even if it's devoid of merits.
Dharma is similar to electricity that enters our homes and manifests differently depending upon the appliance it powers. Each appliance has its own nature and a fan can't dream to be a TV.
Krishna earlier indicated (3.33) that suppression doesn't lead us anywhere. Adopting other's reality is suppressing one's own reality. Suppression leads to exclusion whereas reality is the sum of all the individual perceptions as in the case of the blind men and the elephant.
Source - Daily World