Stat padding is all about intentions and impact. If a player does everything in his power on offense and defense to help his team win regardless of the teams roster then that is not stat padding. If a player cherry picks on defense and only get his numbers on offense that has little impact on winning then that’s stat padding.
How can you tell who's intentions are pure though? You can play hard, and still lose, and it will look like stat padding if you got yours. And plenty of players cherry picked or didn't play defense at all. You can't gauge effort because everyone's demeanor is different. Some players play hard, but it looks lackadaisical on the court. Some have brash personalities that are always aggressive, but it looks like they're being selfish.
Stat padding is all about the narrative, because everyone does it. Whether or not it leads to winning basketball is based on if they like the player.