What effect do press releases have?

Question

Marketing

I have long been interested in the topic of press release distribution.
Interested in the English side.
I saw the prweb service a few years ago, now it has negative reviews and has no desire to contact it. But I saw on fairly trusted sites that you can buy the placement of an article on buzzlike for $ 200-250.
Why is it so cheap or what's the catch? They don't give traffic?
I understand that the effect partly depends on the release, but I'm not interested in the effect of following the link (although this is also the case), first of all, the transition to the article. Is it somewhere in the dark corners of the site?