I find this far too black and white. There's a lot to gain from conversations where you can't change the other person's mind. If you see making them agree with you as the only positive outcome, I can see why you'd give up arguing with people, but you're losing out on a lot of potential benefit.

I also think it's too adversarial. The author's claim, "If you genuinely believe something others don’t, that’s not a debate to win. That’s an edge," is not very persuasive, because you communicate far more with teammates, bosses, and subordinates than with enemies and competitors. Most of the people you communicate with on a day-to-day basis are people who can be dealt with more profitably through cooperation.

"You Can Only Change Yourself" is another far too absolute conclusion. You change and are changed by everybody you come in contact with. Every conversation is a chance to influence someone. If you can't make them see your point right away, you can sow the seeds for a future insight. Or you can clarify why you disagree. You can change their mind from "this person doesn't understand the problem" to "this person cares about an aspect of the problem that I don't think is primary."

I think the author should broaden their idea of what can be achieved in talking with someone they disagree with. It won't help them win arguments, but it will help them reap more benefit over time.