“Bought links” are a bit of a dirty word in the SEO industry - and for good reason - in 2022 your link acquisition strategy should not be built around buying links. In the past, marketers used to pay websites to post their client’s content & link back to their client’s website, often on mass scale & with content that was poorly written & didn’t have any relevance or connection with the website it was posted on. Google saw this as manipulation tactics & penalised websites who did this.
However, paid for links do essentially still exist & they aren’t all bad - you just need to label them correctly. If you take out an advertorial in a newspaper, for example, you’ll likely get a paid-for link, but this isn’t bad, you just need to make sure you attribute any sponsored links with the “no-follow” & “sponsored” tag to let Google know that you’ve paid for that link through an advert.