Commerce wise there is a breakpoint. Pride wise even at a point you have to think of family members and legacy. At any point the amount of effort and failure to try to drag someone else down if instead was used to improve standing, region, diplomacy, or development to attempt to rival would be far more realistic and relatable. Diametrically opposed or being a foil does not have to be morally bankrupt and mentally inept. As proven with the slave trader, treating their merchandise well to sell for better margins is just good business even if owning another person is morally wrong.