When you have great players on your roster, your number one priority is making sure those guys are happy. Building around them has no value if they're eyeing the exit because you fail to keep your promises or don't treat them like they deserve to be treated, considering their worth to your franchise. That's something that Jerry Jones has been struggling with. The Spurs, not so much.
De'Aaron Fox deserves all of that money. He's a great fit for the Spurs, and they're going to make a playoff run with him on the roster. He needs to be happy to be there.