Both are impotent.

If you concentrate on backlinks means it automatically generate the traffic.

Both are most important for Any kind of website.

Traffic is important.

Getting backlinks will improve your ranking and also the traffic. so better to improve backlinks.

Traffic or backlinks?
 

Backlinks are links that travel from another website to your website. They can come from social media sites and directories, but they most often come from blog posts and the content of other websites. Ideally, those links come from other relevant websites within your niche and industry.

backlinks are generally considered more crucial. Backlinks, which are links from other websites to your own, act as "votes of confidence" that signal to search engines the value and trustworthiness of your content, positively impacting your rankings.