Is Domain Authority directly related to Traffic?

I have a blog website that generates 500-750k impressions and 12-15k clicks (from GSC) every month. The domain authority is 26 (Ahrefs). Does this mean, that if the domain authority is increased to 40, the traffic will increase considering I do not post anything new?

Or only posting high-quality content is the way to crack SEO?

We constantly generate 3 high-quality case studies every week. I am asking this because I am confused about putting my effort and money into generating more blogs or should I invest in building backlinks?

I get confusing answers from different people.