https://www.oddschecker.com/boxing/mikey-garcia-v-jessie-vargas/winner
Looks like practically every casino disagrees with you, Garcia is the heavy favorite at between 1/6 and 1/5 on practically every platform.
Yep, that's why this is a good fight for Mikey. Because this time he is the favourite and it seems that he has a good chance to pull this off before he can go for Manny Pacquiao or other good fighters in this talent laden division. Vargas advantage is that he is comfortable in this weight class however, he hasn't fight any notable boxers yet, except for Pacquiao and Bradley which he lost.