First of all: lies, damn lies and statistics. Even if we had hard raw data on a census of a population, we are going to interpret the causes differently. Because there never is one answer to a sociological issue. Truth also doesn't determine the best course of action for any given society either.

Tame example: say that we know that objectively 100% of the time that browsing Facebook leads to depression. Okay... what do we do with this? Do we force facebook to change, maybe even ban it from a country? do we strongly regulate people using Facebook? Maybe only regulate minors? How does that information affect Instagram or any other Meta product? One "truth" doesn't answer these questions.

Second of all: debate is ultimately communication, and communication is about being able to express your own thoughts, often while trying to appeal to other person's thoughts. These core factors of society are important no matter the topic. It should also ideally teach one to consider multiple points of view and make for a more well rounded understanding on comlpex issues, but well... here's the article talking about modern debate.