hello, can i ask some question? is churn and burn

Is Churn and Burn methos is can use for 2019 ? and if can work if just for legal sites? ilegal sites also can ?

Because i have see so many my competitor in google some week can up in rank 1 2 or 3 in google with good keyword, and then i check the sites, is no have a good backlink .

I build my sites with a good backlink but can lose with sites is have much no good backlink in the sites but can rank in google..

Thank you So much