Astroturfing on reddit has been a thing for over a decade and has really accelerated over the last few years. There's several companies where literally that is their business model to promote your product or service on reddit. I saw one for sale on acquire.com a while back for 7 figures
It's so painfully obvious too. On my local subreddit: "what's the best ice cream shop in $CITY?" Check their post history, one "lol" on a cat pic on /r/aww 8 months ago. 4 lines of code could catch this.
There's the classic search "hack" of adding site:reddit.com to any product recommendation search, to find "real" recommendations.
Most of the time this is going to find 5-10 posts, each with only a dozen comments and a dozen up-votes. And yet it feels do much more real than whatever at the top of Google that many people will trust these reviews.