Questions about Backlinking gigs on Fiverr

There are a few job posts on Fiverr that guarantee your website DA will increase by 50 ~70 for about $200 - $300. Does this even help you gain traffic? I audited some of their reviews by going into reviewer's websites and running them on semrush on my own. Some of them really seemed legit.

I know backlinking services are mostly garbage on fiverr, but are there some legit services on fiverr?