To be honest, PBN's are nowhere near as effective as they were a couple of years ago. The chance of getting a manual action against your site is a lot higher.
If you were going to drop a few thousand dollars on buying backlinks, you don't want to have your site de-indexed by Google in 6 months without getting an ROI.
Non-English versions of Google are more linens and are still easy to game for PBN's.
Also, all PBN's are not all created equally. Making sure the domain isn't dropped, different whois details/domain registrars/hosting providers. Also putting relevant links to sites other than what clients have paid for to make this look more legitimate.
Niches with big competition like Pharma/Gambling/Game Hacks/Lead Gen will continue to user PBN's, but bigger SEO's will be diversifying their link building portfolio by building more whitehat links like guest posts and then sending more questionable links like PBN's to them as a tier 2 backlink.
On that note, there's also a technique, forgot the name, but it's basically anti-SEO where they intentionally push a competitor's pages onto a PBN with the intent of getting it detected (and penalized) by Google.
Had a competitor do this to a site with a bunch of really weird porno links.
Kept happening for months. I'd disavow them, 10x as many would show up weeks later. Eventually I lost interest fighting and just stopped disavowing them.
There was never any penalty and from what I could tell the extra links actually helped our rankings! After about 18 months the links stopped. No clue what happened.
It's called negative SEO. There was a Google update that is a bit more lenient so your competitors can't negatively spam your site.
Unless your competitor had some serious dosh to mass spam your site on PBN's, they would most likely being using a tool like Xrumer or GSA where you can purchase a 100k backlink blast for as little as $5
Companies are actively engaging in negative SEO all the time too. My friend used to work at a shady SEO shop in Florida and they used it often. Their clients don’t seem to care how it gets there since they mostly pushing affiliate ads, not a sustainable long term business.
What you describe at the end isn't whitehat. Whitehat (according to Google, from what I can gather) is focusing on site experience and just ensuring search engines are facilitated in indexing.
True, building any sort of backlinks are aganist Google's ToS. But that doesn't mean legitmate don't do it. You just need to be smart about it and make sure it looks "natural" to Google.
I wonder why non-English versions of Google are behind on this (I agree that they are), surely much of the Google search algorithm is language independent?
Less data available in smaller market for the algorithms to work with, noise vs. signal ratio.
And it’s a snow balling effect, they still need to provide results to users, and with more spammy websites in a market the average website can get away with more dodgy tactics.
I agree they have to make adjustments, however factors such as number of backlinks from high DA sites, user dwell time on page, schema markup, meta data structure, https, domain age, mobile friendliness, page speed etc. don't require an understanding of language.
To be honest, PBN's are nowhere near as effective as they were a couple of years ago. The chance of getting a manual action against your site is a lot higher.
If you were going to drop a few thousand dollars on buying backlinks, you don't want to have your site de-indexed by Google in 6 months without getting an ROI.
Non-English versions of Google are more linens and are still easy to game for PBN's.
Also, all PBN's are not all created equally. Making sure the domain isn't dropped, different whois details/domain registrars/hosting providers. Also putting relevant links to sites other than what clients have paid for to make this look more legitimate.
Niches with big competition like Pharma/Gambling/Game Hacks/Lead Gen will continue to user PBN's, but bigger SEO's will be diversifying their link building portfolio by building more whitehat links like guest posts and then sending more questionable links like PBN's to them as a tier 2 backlink.