Not necessarily scammers but certainly spammers using bots to create GN accounts to push products.
The bot scans old posts looking for keywords. It uses AI to create a seemingly relevant post and inserts a link to the product they are trying to sell into the post.
The context of the thread and the product being pushed are often unrelated. If someone is pushing, say, a video game, the bot might pick up on any word vaguely linked to gaming.
The top four words linked to gaming are: streaming, play, computer and competition. So any threads about colds, digital TV, grandchildren coming round to play, issues with a computer or maybe entering or winning a competition could be picked up and spammed.
As GN is post-moderated and relies on members to report spam, often the spam post will sit there until it has been reported, removed and the spambot account blocked.
Meantime, genuine members come along, think the post is genuine and respond to that post or ones before it.
The clue is that the ID of the poster is often a name like alanbrown, charlesdavies, edwardfinch and the post will contain a link to a website selling a product.