This is a great example of a strawman argument. I didn't say anything about teams, or "employees paid solely to post on social media". You injected those details, because you think that they make the idea of an astroturf campaign seem farfetched. But we know that such campaigns happen in other contexts, sponsored by entities with less money to throw around. Why not here? And why do we need to know the mechanics, if all we care about is whether or not it's happening (and maybe, if it's not self-evident, what the goal of such a campaign is)? We don't, really.
Sure, so it sounds like we've got a different idea in mind for what this sort of work would look like. Totally understandable!
In your opinion then, what would a Google-run astroturfing campaign roughly look like? Sounds like this article is an example, right? I'm not asking for insider info, I'm just curious about your mental model on the basic mechanics.
Personally, I think the case "other entities with comparable resources do this, so Google probably does too" isn't super convincing to me. IMO, the null hypothesis "Google has lots of nerdy fans who'll happily post positively about it for free" is a lot reasonable, but perhaps there's something I'm missing.