It’s completely within the realm of expectation that you could have a nation-state level initiative to propagandize your enemy’s populace from the inside out. Basically 2015+ Russian disinformation tactics but massively scaled up. And those were already wildly effective.
Now extend that to more benign manipulation. Think about the companies that have great grassroots marketing, like Doluth’s darn tough socks being recommended all over Reddit. Now remove the need to have an actually good product because you can get the same result with an AI. A couple hundred/thousand comments a day wouldn’t cost that much, and could give the impression of huge grassroots support of a brand.