PBN's work, but the cost of remaining competitive is gradually getting higher. Expired domains are getting more expensive, you can't just have a crappy domain full of spun content and linking only to your money site and expect it to be effective, or not put you at higher risk of a penalty.
SEO is a money game more than ever. If you can afford a high end, relevant domain for your money site and then your own independent PBN for it with a good writer churning out great content on both the PBN and money site, you probably will rank well. Nothing in SEO in certain though, I have used PBN services with great success, and also I see competitors ranking without all of this, so it's still a gamble in the end.
I'm not sure how Google would compile their results without a weighted emphasis on links. Everyone can build a whole site of authority content, but what makes the difference between that and an established site? Links.