For what it's worth, I think that a lot of the problem comes from a decline in media discourse. So much is expressed in slogans - 'on its knees', 'off a cliff', 'under a bus', and name calling - 'Two tier Keir', Robber Reeves' etc. They start on social media or in the press, and get repeated in conversation and pass for 'debate', but they prevent real analysis or even discussion, as nobody knows what anyone else is talking about. Anyone can repeat a 'catchy' slogan, and doing so means that they can have a dig at something or someone without having to think too deeply, and it puts people off replying, or even posting in the first place.
Obviously this suits populists, as they don't want people to ask incisive questions, or talk to one another in ways that challenge the simplistic soundbites.
I heard an interview recently in which someone said that the NHS used to be on its knees, but now it's on its face
. That sort of thing is meaningless, and the whole sloganising lends itself to playground jeers and trading of insults instead of a discussion of actual issues.
I've been on GN more than five years, and whereas there have been heated threads in all that time, and disagreement about policy and personnel in politics, it's since it became obvious that Labour would win the election that the slogans and sneering has come in. It got so bad that some people were banned, others have left, and this has given the green flag to sneering and point scoring that doesn't debate very much. I suspect bots are behind some of it, but I can't be sure. What I am sure of, though, is that if people know that there are those looking for ways to shout 'Gotcha!' because their post can be read in more than one way, or that there is a minor inaccuracy or typo, it stops 'conversation' and leads to a much more stilted discourse, which is not what GN (or most discussion boards) does best.
If GN ceases to be somewhere for discussion, life will go on. More posters will leave, and find other places to post or other things to do with their time. But if discussion stops everywhere, and is replaced with second hand slogans, democracy is at risk, which is a lot more serious a prospect.