PBN plays a big role to rank the site in the higher rank.PBN are a shortcut method to get high quality backlinks in large quantities.Blog Commenting describes a relationship between blogs ,bloggers and blog readers.you can use your blog comments to connect with people.
PBN, as the name suggests, is a network of blogs redirecting to the main site. Hence, there's a higher chance these juicy links may uplift rank for the main site. Blog comments also tend to perform well. However, deeply depends on blogs chosen and quality comments which doesn't appear spam.