The line is iconic, but I’ve literally never seen the comic from the article.
Xkcd might be more iconic as a whole, but I can’t think of a single comic that approaches “on the internet no one knows your a dog” meme, but it’s clearly transcended its origin.
I think most of the people complaining don’t seem to realize that this was a one-off in The New Yorker from before most people had the Internet, and not a currently running web series.