Trolling existed before the internet. It is just satire.
And the reason this issue exists is, as I think you imply, is why trolling is effective and why satire still exists as a form of comedy: people are usually totally unconscious of their own biases, particularly when they are examining the bias of others (particularly today, admitting that you are biased is a form of self-hate when so much energy is devoted to finding biases in others...note that people equate struggle sessions with greater equality, it is all about other people).
I will also say, and this is unappreciated: people who talk a lot about trolling often do not get satire at a fundamental level, they lack any ability to introspect or find humour in their own irrationality or that of others, everything is just black and white (and I will venture: afaik, this forum is also the largest congregation of such people anywhere on the internet...yc is the white whale for trolls), and there is really nothing you can do about this. Again, it is why trolling exists.
Satire is one of the most important forms of comedy. There is no other form of comedy that is more closely associated with political discussion. The internet has been a wellspring for this kind of humour, it is wonderful (it is no surprise that the same people who complain about trolling are also vaguely intolerant of anyone with opposing political views to their own, anyone who opposes them is a troll and must be removed from the internet...again, this thinking predates social media by a number of years, the only change is people thinking that social media has changed anything).