He absolutely was snubbed by any relevant metric. Of the current top 25 scorers in the league, here are the only guys who did not make it to the All-Star game and their position on the PPG leader board:
#11 De'Aaron Fox
#19 Desmond Bane
#22 Lauri Markkanen
#25 DeMar DeRozan
At the time voting was completed, I believe Fox was 8th so his absence is even more egregious. Those other 3 guys are on teams which are below .500. And it's also worth noting that Fox is now 3rd in the NBA in Steals Per Game too. He hasn't played his best ball in January which weighs more heavily into this result than it should. In terms of both individual performance and team success, he more than earned an All-Star spot this season.