What is left after honesty is better for you.
Clean profit versus wrongful gain
Ibn Jarir explains that the profit left after giving people their rights is better than taking their wealth wrongfully. Ibn Kathir links it to the verse that the bad and the good are not equal, even if the bad is plentiful. Shu'ayb added he was not their guardian: do this for Allah, not to be seen.
Payday comes and it is smaller than your friend's, who cuts corners. You feel like the fool for being honest. The smaller, clean amount carries blessing. And nobody is checking but Allah.
Honest money is less, so honesty is a loss.
What remains lawful from Allah is worth more than a bigger pile gained wrongly.
Look at your next payment and thank Allah that it is clean, whatever the size.