Pretty much nothing, it was always bad. Although, it has gotten worse after they added steam points and the ability to put a special emote on someone's comment/post which gives them steam points so now people often purposefully post some cringe just to get clowned upon and collect the points, or plagiarize/make meme posts so actual information becomes rare.

The truth of the matter is that the core demographic for steam forums are either children or gopniks, everyone else rarely even look at Steam let alone post/comment. Very little moderation doesn't help things also.