I think the primary argument against it basically boils down to the fact that the internet hasn’t actually changed things as much as most people of our generation who grew up with it think, and many of the changes are better, not worse.
1) For harassment, it would be hard to do worse than the harassment we had in the past. Open racism has certainly declined since the 60s/70s. There was significantly more actual violence against people during that time than today.
2) Misinformation was certainly more prevelent in the past. Did you know that in 1970 30% of Americans thought the moon landing was faked? The number now is much much lower and has only gone down.
3) The idea that foreign powers were influencing America was certainly a lot bigger in the past. The “red scare” was a thing. People were mistrusting of thier neighbours and accusations of being communist abounded.
I think the main thing the internet has done is surface the craziness so that more people know about the fewer actual number of crazies.