Not sure if that was hyperbole, but since you ask, yeah I think it could actually bring about the downfall of humanity. For example, what if climate science videos were being significantly brigaded by bots controlled by oil companies? Might not be that far-fetched. If we fail to communicate effectively about issues like that, we could very well see the downfall of humanity. Even "organic" brigading by the anti-vaxx crowd on related videos seems like an existential threat.
>>>For example, what if climate science videos were being significantly brigaded by bots controlled by oil companies?
I think we need to separate the bot problem from the organic humans. BOTS should be the issue that is countered, regardless of whether they are upvoting or downvoting content. Humans expressing themselves is just grass-roots organizing.