Earlier quoted context omitted.
Maybe. But content on reddit has better provenance data than content on the web in general; reddit has found a version of identity that strikes the right balance. You can take an arbitrary comment and be able to tell with reasonable confidence whether there's an at least somewhat "real" user behind it, in a way that you just can't for a random blog or a product review anywhere else.
That's what the marketers want you to think
Going on various social media platforms to decide on a purchase has already been an established pattern for more then 10 years. That's more then enough time for even the biggest corporations to act on.
Do keep in mind that the influencing agency doesn't actually have to write comments. Machine Learning is super good in determining if a given comment is about [topic], and wherever its a [positive] or [negative] comment.
I'm sure people already know that there are a lot of agencies around which sell you votes on relevant platforms, so any given company can - for peanuts(!) - just upvote positive 'real' comments and downvote the same for the competitors products etc.
There is very little you can 'trust' on the internet, as its just too profitable to spread propaganda through it. there have been several people that publicly admitted that their whole job was to derail critical conversations on various platforms. So even if you put in time and produce a quality comment... there are people who get paid just to write comments to make it look like misinformation.