Right
圭 supplies the sound - guī drifted to jiā, an irregular but historically attested shift.
圭 is a ceremonial jade tablet (two
土 stacked, an etched stone of rank), so the right side also faintly suggests preciousness - fitting for a 'fine' person. Same phonetic family:
街 (street),
蛙 (frog),
挂 (hang).