I agree, he never win round 3, but maybe because he is getting ready for 3 rounds fights and just do enough to win a 3 rounds fight.
We have seen many fighters seem to gass in 3 round fight but able to fight 5 rounds if getting ready for it. Best examples being Romero, Kevin lee, mendes, even Usman.
We have never seen Zabit KOed, dropped or even stunned in a fight, the day it will happened in a later rounds, I ll say his cardio is an issue, until that he is winning fight and still undefeated in the UFC. I favor him against every 145er not named Max Holloway.
Do you want to AV bet he beat Ortega ?