I dunno if I want a "debate" or anything, but certainly the ability to openly consider things like, for example, what an independent Scotland might look like. As it stands pro-indy people often declare it'll be a riproaring success from the start, while anti-indy Scots fear-monger about Nicola Sturgeon and the SNP being some sinister totalitarians and from south of the border you get some pretty condescending stuff about being a "third-world country". That's just one example, but I imagine it's not uncommon across various subjects.

My friends are all pretty level-headed and good to talk to, but online things tend to get very tribal and center around these exaggerated points as if there's a referee keeping track of the points you scored on your "opposition".