The issue is not that people tend to follow the herd, nor that people try to influence each other’s opinions, those are just facts of life. The issue is when someone creates a fake herd that only they control.

If 100 different Twitter accounts all weigh in on a thread, arguing for one side, but they are all secretly controlled by one person, that creates a false picture of widespread support for that person’s stance.

It’s true that traditional advertising has always been used to create artificial buzz around candidates, and this is often a bit manipulative. But creating a crowd of fake supporters, with fake photos and bios, and deploying them in conversations with unsuspecting real humans, is a whole different level of manipulation.

There is absolutely no difference. Why is it ok for politicians to pay for signs to be posted in front yards, show to all of the neighborhood "network". Yet, the same action is somehow evil when the "neighborhood" is instead a social media platform?

It’s because this exists in meatspace where there is almost always a significant Proof of Work required. This helps limit/prevent the most egregious abuses.