Online is a facet of the real world and a place for a significant amount of information gathering and discourse so dismissing it entirely is a bad mistake as well.
The dynamics are very different, especially the complete lack of consequences for lying, cheating, and uncivil discourse. It used to be that you needed to assume you're talking to a shill/liar at all times but now you can't even believe you're talking to an actual human. Regardless, a lot of people get a lot of influence online; it is impactful and it matters even if we wish it didn't.
One of my favorite quotes is "on the internet nobody knows you're a dog" because of how many different angles it can cover. My bright eyed youth took it as a meritocracy of ideas enabled by anonymity and free access - anyone can talk even if you don't normally talk to them or even think "they" are valid. My jaded cynic side sees the ability for predators to lurk in plain sight with no recourse. A more rounded view simply cautions that not knowing who is "on the other side of the line" means you really can't get a lot out of a conversation there.
I have no idea if it's true but I've heard the folk tale that saying "moshi moshi" to answer the phone was because trickster foxes could pretend to be people but couldn't pronounce moshi moshi so you are least knew you were talking to a person. Everything old is new again.
"Online is a facet of the real world and a place for a significant amount of information gathering and discourse so dismissing it entirely is a bad mistake as well."
Having spent time online since the dawn of home internet it would be impossible for me to disagree with this sentiment more strongly. I've been dragged kicking and screaming over the course of the last 3 and a half decades to the sullen conclusion that the internet may well be the single largest mistake our species has ever or will ever make short of someone freaking out and actually triggering a full scale nuclear exchange. All of the negative dynamics you list are demonstrably bleeding into the larger culture, with expected results, and that's before even factoring in naked propaganda, poorly camouflaged advertising, and ubiquitous surveillance.
I totally agree with you on every point. I think we've done a thing with the internet that our psyches aren't ready to handle.