Links from the top 20-50 websites to improve ranking?
 

I see a few other websites that have a few sentences or paragraph with some of the top 20-50 websites in the niche and all of porn on a random side page named "other recommended websites" pornhub youporn xvideos and then a lot of private membership websites as well..

Is this:

A. legal
B. does it help in any way with website ranking by having all these external links?

pornhub youporn xvideos bought those links.

Anyone else?