One of the things they teach you in academic philosophy is to anticipate the strongest argument of the other side. If you are able to address the strongest argument of the opposing side that you can think of, then you have done your job.
This is also related to sincerity. If you argue against the easy targets while knowing that there is a stronger argument that you haven’t addressed, then it is intellectually dishonest to ignore that stronger argument. Because ultimately you are after the truth and that stronger argument might prove that you are wrong. So you must do your due diligence to see if you can address that argument and see where that leads you.
This skill of anticipating what the other side can say is invaluable. It sharpens your ability to understand how concepts are related to each other and what is at stake in any given debate. And “debate” is not something that just happens in the classroom or the courtroom. If you are negotiating a price. If you are interviewing for a job. If you are asking your boss for a raise. If you are trying to negotiate with your spouse about something. These are all different kinds of debate that happen in day to day life. If you can stop and think about what the other side is thinking, that not only makes you a better negotiator/debater, it also creates opportunities for empathy. Imagining how things are on the other side can make a huge difference on a number of levels.