Yeah, Internet "discourse" has gone downhill and rightly the causes have been identified. It's the combination of social media (which isn't social at all) and ubiquitous smartphone-usage. I admit I was spending a lot of time in the 2000s in the comment sections/forums of several newspapers and news sites. You had more meaningful conversations due to the circumstances me thinks. You'd write your commentaries sitting at your desk using a PC or Laptop with specially confined time dedicated to writing comments.

Social media is all well for spamming your products or gigs and such, but definitely not suitable for deeper conversations/exchange of ideas. Yeah, post a meme instead. People feel the need to reply as soon as they are "alerted" bc they are logged on 24/7 on their smartphones. Those "conversations" are to a great extent "Trolling by default".

Unfortunatley, the situation won't change much in the foreseeable future since the more considerate people leave crappy FB or twitter, leaving the rather unpleasent peeps in the ring.